Textual entailment is a relationship that obtains between fragments of text when one fragment in some sense implies the other fragment. The automation of textual entailment recognition supports a wide variety of text-based tasks, including information retrieval, information extraction, question answering, text summarization, and machine translation. Much ingenuity has been devoted to developing algorithms for identifying textual entailments, but relatively little to saying what textual entailment actually is. This article is a review of the logical and philosophical issues involved in (...) providing an adequate definition of textual entailment. We show that many natural definitions of textual entailment are refuted by counterexamples, including the most widely cited definition of Dagan et al. We then articulate and defend the following revised definition: T textually entails H = df typically, a human reading T would be justified in inferring the proposition expressed by H from the proposition expressed by T. We also show that textual entailment is context-sensitive, nontransitive, and nonmonotonic. (shrink)

Mit den Fortschritten in Generativer Künstlicher Intelligenz, Large Language Models, Brain-Computer Interfaces und genetischen Eingriffen gewinnt auch der Transhumanismus an Relevanz. Der Transhumanismus ist ein beliebtes Thema der Medien und wird in Tages- und Wochenzeitungen sowie im Fernsehen gerne aufgegriffen. Außerdem gibt es inzwischen viele Filme, die den Transhumanismus thematisieren, z. B. die Dokumentation „Endlich unendlich“ (2021, Regie: Stephan Bergmann). Der Transhumanismus wurde in Österreich auch Gegenstand einer Verschwörungserzählung, über die der Bayrische Rundfunk aufgeklärt hat. Auf den Wahlplakaten der „Partei (...) für Gesundheitsforschung“ ist der Transhumanist Aubrey de Grey abgebildet, der ein in Cambridge lebender Brite ist, aber auf Plakaten in Deutschland dargestellt wird. Diese und weitere Entwicklungen machen es notwendig, sich mit dem Transhumanismus aus wissenschaftlicher Perspektive auseinanderzusetzen. Was ist der Transhumanismus? Alle sprechen von Transhumanismus, aber was der Transhumanismus letztlich ist, bleibt häufig unklar. Der Transhumanismus (TH) ist eine philosophisch-technologische Bewegung des 20. und 21. Jahrhunderts, die es sich zum Ziel setzt, mittels neuer Technologien den Menschen grundlegend zu transformieren. Wichtig ist dabei, dass sich der TH nicht mit den Optimierungsbestrebungen in der Gesellschaft oder technologischem Fortschritt gleichsetzen lässt. Vielmehr verstehe ich unter TH die Gruppe, die sich um die Organisation Humanity+ in Kalifornien versammelt und die Personen, die sich explizit alsVertreter*innen des TH verstehen. Der TH hat eine ganz eigene Agenda, eigene Institutionen, Organisationen und Publikationsorgane.4 Zu den Themen und Visionen gehören die Lebensverlängerung von mehreren Hundert Jahren bis zur Unsterblichkeit, Kryonik (das Einfrieren des Körpers, der wieder aufgetaut werden soll, wenn nach transhumanistischer Vorstellung Unsterblichkeit ermöglicht werden kann), umfassendes Enhancement und die Verschmelzung von Körper und Technik sowie Beseitigung allen Leids, aller Krankheiten und Aufhebung des Alterns. Der TH strebt danach, mittels Technik neue Sinnesfähigkeiten zu erlangen und neue (virtuelle) Erfahrungswelten zu erschließen. Außerdem wird von vielen Transhumanist*innen auch die hochspekulative Vision des Mind Uploading vertreten, die streng genommen dem Posthumanismus zugeordnet werden muss Gemäß dieser Vision soll durch das maschinelle Lesen des Gehirns der ganze Mensch auf ein externes Medium hochgeladen werden können. Die Vision des Mind Uploadings ist aus naturwissenschaftlicher Perspektive hochumstritten, ist aber ein sehr beliebtes Motiv, das auch außerhalb des TH Wirkung zeigt und in viele Science-Fiction- Filme Eingang gefunden hat (z.B. die Amazon Serie „Upload“, 2020, Regie: Greg Daniels). Das Bestreben des TH, den Menschen grundlegend zu transformieren, wirft zunächst die Frage auf, wie der TH den Menschen überhaupt versteht. Dieser Frage nach dem Menschenverständnis des TH habe ich mich in meinem Buch „Über-Menschen. Philosophische Auseinandersetzung mit der Anthropologie des Transhumanismus“ gewidmet. Philosophische Anthropologie bezeichnet die wissenschaftlichen, philosophischen Reflexionen auf den Menschen. Welches Menschenverständnis vertritt der TH und lässt sich unsere Anthropologie auf dieser Grundlage weiterentwickeln? Das Buch gliedert sich in drei Teile: Teil 1 führt zuerst in die Bewegung des TH ein, worauf Teil II aufbaut, der sich mit dem Menschenverständnis des TH beschäftigt. Teil III betrachtet schließlich heutige Optimierungsbestrebungen in der Gesellschaft sowie neue Ansätze für die Technikanthropologie (z. B. Kritischer Posthumanismus und Neuer Materialismus). Die nachfolgenden Kapitel dieses Aufsatzes sind ein Ausschnitt aus Teil II, der Untersuchung des transhumanistischen Menschenverständnisses. Dieser Aufsatz widmet sich dem „genetisch codierten Menschen“ im TH, also der transhumanistischen Sicht auf den Menschen als jemanden, die*der vollständig von ihren*seinen Genen bestimmt ist. Der genetische Diskurs ist nur einer von fünf im TH dominanten Diskursen, die das transhumanistische Menschenverständnis ausmachen. Zu den anderen Diskursen bzw. transhumanistischen Bestimmungen des Menschen gehören: der Diskurs um die „Natur des Menschen“, der Maschinendiskurs – die Bestimmung des Menschen als Maschine –, der neurowissenschaftliche Diskurs – die Gleichsetzung des Menschen mit dem Gehirn bzw. Neuronalem und zuletzt die metaphysischen Verhältnisbestimmungen von Geist und Körper (PUZIO, Über-Menschen, Kap. 4). Diese transhumanistischen Bestimmungen des Menschen werden am Ende ausgewertet. Ohne die Ergebnisse dieses Kapitels im Detail vorwegnehmen zu wollen, kann für die Gesamtuntersuchung des TH gesagt werden, dass das transhumanistische Menschenverständnis sich als hochproblematisch erweist. Die transhumanistischen Argumentationsstrukturen sind nicht tragfähig und der TH behauptet sich auf die Naturwissenschaften zu berufen, widerspricht allerdings den aktuellen Ergebnissen der Naturwissenschaften. Dies wird in den nachfolgenden Kapiteln gut deutlich werden. Der TH hat ein reduktionistisches Menschenverständnis und reduziert den Menschen beispielsweise auf „Information“. Viele Ausführungen sind diskriminierend z. B. gegenüber Kranken, Alternden und Menschen mit Behinderungen und letztendlich wird sogar jeder Mensch, auch der gesunde junge Mensch, gegenüber der Maschine abgewertet, die aus transhumanistischer Sicht den Menschen weit übertrifft. Im weiteren Verlauf der Arbeit werden sogar „ideologische Elemente“ im TH identifiziert. Daher wird in der Arbeit abgelehnt, den TH als Grundlage für die Weiterentwicklung der Anthropologie zu verwenden und stattdessen werden im letzten Teil der Arbeit alternative Ansätze für die Technikanthropologie präsentiert. Wie bereits erwähnt, richtet sich die Kritik am TH jedoch nicht gegen die heutige Optimierung in der Gesellschaft, die ebenfalls im letzten Teil der Arbeit diskutiert wird. Optimierungsbestrebungen hat es schon immer gegeben und sie werden nun durch neue Technologien weiter verändert, sie sind aber nicht mit der Bewegung des TH gleichzusetzen. Das Kapitel ist eingebettet zwischen dem Maschinendiskurs (Mensch als Maschine) mit seinen Ausführungen zu Information und Kybernetik und dem neurowissenschaftlichen Diskurs („Der Mensch ist ihr*sein Gehirn“). Es wird im Folgenden der genetische Diskurs im TH untersucht, also wie der TH den Menschen vollständig auf Gene zurückführt, und dies schließlich kritisch geprüft. Sind „gute Gene“ alles? Kann der Mensch vollständig über ihre*seine Gene bestimmt werden? Und was hat es mit der trügerischen „genetischen Information“ auf sich? Zunächst wird der genetische Diskurs im TH dargestellt, also die genetischen Ausführungen des TH präsentiert (Kap. 2), danach wird der Blick auf den Gebrauch der genetischen Metaphern im TH gerichtet (Kap. 3) und zuletzt werden die genetischen Vorstellungen des TH kritisiert (Kap. 4). Der Aufsatz schließt in Kap. 5mit einer (vorläufigen) Zusammenführung der Ergebnisse und einem Ausblick. (shrink)

Es ist wahr, die frühe Neuzeit hatte nur einen Descartes. Aber sie hatte hunderte schreibende Gelehrte. Auch solche, die Descartes und allen anderen zeigten, wer was wo schon geschrieben hatte. Solche Universal-Gelehrten dachten an den einzelnen Schreiber, sie halfen ihm absichtlich nicht, die Quellen zu verbergen, sondern sie zu finden. Keine Träumereien an französischen oder schwäbischen Kaminen, sondern effiziente Arbeit am Jesuitenkolleg waren Ziel und Inhalt z.B. der Bibliotheca selecta , in der Antonio Possevino SJ das Bildungsprogramm der Jesuiten (...) mit einem Literaturkanon und allgemeinen Erörterungen zur Bildung und Ausbildung versah. Dieses Handbuch stellt, entgegen gewissen Anzeichen, kein System der Wissenschaften dar, sondern konstruiert deren Gemeinsamkeit mittels der direkten Zwecksetzung zum Seelenheil der Menschen, woraus einerseits die Notwendigkeit einer Psychologie des Lernens, andererseits eine größere Unabhängigkeit der Wissenschaften von einander resultiert. Mit seiner Mischung von humanistischer Gelehrsamkeit, frommer Finalität, Kultur des Individuums und allgemeiner Nützlichkeit ist die Bibliotheca selecta ein Schnittpunkt von Humanismus und Schulweisheit. (shrink)

Die Frage, ob Karl Jaspers ein Kantianer ist, wird nicht nur kompetente Jasperskenner überraschen, sondern auch die meisten Philosophiehistoriker, die mit der Geschichte der Philosophie der Neuzeit und Moderne vertraut sind. Denn einerseits werden nicht nur die meisten Jasperskenner, sondern auch die meisten Philosophiehistoriker überhaupt, diese Frage zunächst einmal mit einem gewissen Recht verneinen. Denn der überlieferten Lehrmeinung zufolge, war Jaspers kein Kantianer, sondern ein Existenzphilosoph. Andererseits werden vermutlich die meisten Jasperskenner und Philosophiehistoriker zugestehen, dass Kant für Jaspers zumindest einer (...) der wichtigsten Philosophen war, wenn nicht sogar der wichtigste Philosoph überhaupt. Das alleine reicht aber kaum aus, um Jaspers als einen Kantianer aufzufassen. Denn wer Jaspers als einen Kantianer bezeichnet, wird damit nicht nur meinen, dass Jaspers unter allen großen Philosophen immer noch Kant am nächsten stand und ihn am meisten schätze, sondern auch dass er selbst philosophische Auffassungen und Überzeugungen vertreten hat, die dem überlieferten Idealtypus eines Kantianers entsprechen. In diesem idealtypischen Sinne können und dürfen wir zumindest aus heuristischen Gründen z.B. Augustinus, Plotin und Bonaventura als Platoniker sowie Thomas von Aquin, Trendelenburg und Brentano als Aristoteliker bezeichnen. In diesem idealtypischen Sinne können und dürfen wir auch fragen, in welchem Sinne man Jaspers eher als einen Platoniker oder als einen Aristoteliker verstehen kann. Und in diesem Sinne kann man dann auch mit gewissen Fug und Recht fragen, ob Jaspers den wesentlichen Grundzügen seines Philosophierens zufolge ein Kantianer ist. (shrink)

Predication is a lingual relation. We have this relation when a term is said (λέγεται) of another term. This simple definition, however, is not Aristotle’s own definition. In fact, he does not define predication but attaches his almost in a new field used word κατηγορεῖσθαι to λέγεται. In a predication, something is said of another thing, or, more simply, we have ‘something of something’ (ἓν καθ᾿ ἑνὸς). (PsA. , A, 22, 83b17-18) Therefore, a relation in which two terms are posited (...) to each other in a way that one is said (predicated) of the other is a predication. The term of which the other term is said is called a subject (ὑποκειμένον) and the other, which is said about the subject, is called the predicate. Thus, in a predication the predicate is predicated of the subject; given that being predicated is almost as the same as being said. The relation between being said and being predicated is so close that ‘if something is said of a subject both its name and its definition are necessarily predicated of the subject.’ (Cat., 5, 2a19-26) This, however, is true only about the second genera and not the accidents. a) Nature of relation in predication What is Aristotle’s theory about the nature of the relation in a predication? How does he fundamentally understand this relation? Phil Corkum distinguishes between predication logic and traditional term logic and argues that the relation between subject and predicate in Aristotle is of the latter kind. While in predicate logic, subjects and predicates have distinct roles, they have the same role in traditional term logic. In predication logic, subjects refer, but predicates characterize. Thereupon, a sentence expresses a truth if the object to which the subject refers is correctly characterized by the predicate. In traditional term logic, both subjects and predicates refer and a sentences expresses a truth if both name one and the same thing. He concludes that Aristotle ‘problematically conflates prediction and identity claims’ because while he thinks both subjects and predicates refer, he would deny that a sentence is true just in case the subject and the predicate name one and the same thing. Based on this, Corkum believes that Aristotle’s core semantic is not identity but the weaker relation of constitution, which is a mereological interpretation: ‘All men are mortal’ is true just in case the mereological sum of humans is part of the mereological sum of mortals. b) Aristotle’s theory of predication: one or two theories? Frank Lewis finds an inconsistent gap between the theory of predication in the Categories and that in the later books of the Metaphysics VII, 6. So too Joan Kung, Terry Irwin, Daniel Graham. c) Distinction of ‘being said of’ and ‘being in’ Owen enumerates the texts in which Aristotle’s distinction between ‘being said of’ and ‘being in’ is asserted: OI. 11b38-12a17; To., 127b1-4; Cat. 1a20-b9; 2a11-14; 2a27-b6; 2b15-17; 3a7-32; 9b22-24 d) Predication in Aristotle and the standard ‘S is P’ Marie De Rijk Lambertus thinks that the ‘S is P’ pattern is misleading when it comes to express predication in Aristotle. In his view, ‘The Aristotelian procedure should be described in terms of appositively assigning an attribute (κατηγορούμενον) to a substrate (ὑποκείμενον), rather than ascribing a predicate to a subject by means of a copula…. The comment should be considered an attribute which is said to fall to a substrate, without understanding this procedure in terms of sentence predication.’ e) Aristotle’s predication: bipartite or tripartite? It is a difficulty to make Aristotle’s theories of name-verb predication and tripartite predication consistent. The reason is that tripartite is not consistant with his name-verb structure based on which he says that the predicate term is the ‘verb.’ (20a31; 20b1-2; 16a13-5) The problem is that in a tripartite form like ‘Socrates is white’ we cannot take ‘is white’ as the verb because, based on Aristotle himself, no part of a verb can be significant itself. (16b6-7) However, his assertions about the equivalences between the two structures (OI. 12, 21b9-10; PrA. 51b13-16; Met., 1017b22-30) must mean that they are not inconsistent in his own view. Thus, as Allen Bāck points, ‘Aristotle seems to think that he has a single, consistent theory.’ The sense of saying or speaking as the root sense of rhema makes the relation between predication (saying something of something) and verb more interesting. The use of rhema in the sense of a long expression approves this. In Plato’s work (399ac) where Socrates claims that the name anthropos derives from anthron ha opopen (‘he who examines what he has seen’) we have an onoma from, or in place of, a rhema. 1) Subject The subject (ὑποκειμένον) is that of which another term is said or predicated. Aristotle’s own definition is of a much more philosophical value: ‘By subject I mean that which is expressed by an affirmative term (λέγω δὲ ὑποκείμενον τὸ κάταφάσει δηλούμενον).’ (Met., K, 1067b18) Throughout Aristotle’s work, three kinds of subjects can be found: possible, prime and absolute subject. a) Possible subject Those things that can take the position of a subject in a predication we call possible subjects, no matter they can or cannot take the position of predicate in any predication. All terms except the ultimate predicates are possible subjects because they can take the position of subject. b) Prime subject Those that in any predication can only take the position of a subject and not the position of a predicate are prime subjects. (Cat., 5, 3a36-b2; Met., Z, 1028b36-1029a1) This is the truest sense of subject and belongs only to substances. (Met., Z, 1029a1-2) In fact, ‘that which is not predicated of a subject, but of which all else is predicated’ is a substance. (Met., Z, 1029a7-9) In Categories, besides primary substances (Cat., 2, 1b3-6), individual qualities are also said not to be able to be said of anything else. (Cat., 2, 1a23-29) Aristotle’s examples are a certain ‘knowledge-of-grammar’ (τὶς γράμματικὴ) and ‘an individual white’ (τὸ τὶ λευκὸν). Thus, although substances are indeed in the truest sense individuals and, thereby, in the truest sense primary subjects, other individuals can take the position of subject as well. c) Absolute subject While substances are prime subjects of all other things, there is still something of which substances can be predicated and this predication is not an accidental predication: matter. (Met., Z, 1029a21-24) This predication is, indeed, the predication of a ‘form or this’ on matter and material substance. (Met., Θ, 1049a34-36) The only thing that is absolutely a subject, therefore, and can be a predicate is prime matter (πρώτη ὓλη). (Met., Θ, 1049a24-27) d) Subject and substance The most important thing in being a substance is being a subject: ‘It is because the primary substances are subjects for all the other things and all the other things are predicated of them or are in them, that they are called substances most of all.’ (Cat., 5, 2b15-17) And what is nearer to this position is more a substance as a species is more a substance than a genus.’ (Cat., 5, 2b7-8) e) Primary versus accidental subject A subject is a primary subject in a predication when the predicate is predicated of it as itself. In such a case, the subject is the subject of the predicate qua itself and not qua something else. A subject, on the one hand, is an accidental subject when it is not the primary subject of the predicate that is predicated on it. It means that a subject is an accidental subject when the predicate is predicated of it not qua itself but qua something else. An accidental subject is, therefore, anything other than a substance. 2) Predicate as universal It is evident from our discussion of kinds of subjects that except matter, primary substances (if we ignore both accidental predication and cases of absolute subjects) and other individuals, everything else can take the position of a predicate. Since primary substances are individuals, it results that everything except matter and individuals are capable to take the position of predicate. The immediate consequence of this is that the predicate must be a universal. When individuals cannot take the position of predicate, this position cannot be taken by any particular. Therefore, only universals can be predicated of others. Moreover, albeit universals can be a simple subject (for another universal), they are not prime subjects. The closeness of universal and predicate is to the extent that Aristotle differentiates universal from subject. (Met., Θ, 1049a27-30) 3) Categories or classes of predicates Aristotle distinguishes ten highest classes into one of which each predicate must necessarily fall: substance (or what a thing is), quality, quantity, relation, place, time, position, state, activity and passivity. (Cat., 4, 1b25-27; To., I, 9, 103b20- ; PsA., A, 22, 83b13-23) The substance counted among predicates must refer to secondary and not primary substances not only because Aristotle insists that primary substances cannot be predicated but also from his own examples of the category of substance: man and animal. (To., I, 9, 103b25) However, if a predicate be asserted of itself or its genus be asserted of it, the predicate signifies substance or what is; but if ‘one kind of predicate is asserted of another kind,’ it signifies one of the other nines. (To., I, 9, 103b30) These categories are so comprehensive that no predicate can remain outside them so that even non-being has as many senses as categories. (Met., M, 1089a26-30) a) That whether Aristotle’s categories are merely linguistic or fundamentally ontological is a so much controversial dispute. Some like G. E. R. Lloyd believe that ‘categories are primarily intended as a classification of reality … rather than of the signifying terms themselves.’ b) Although Aristotle’s categories have been historically regarded as a classification of predications, there are some recent commentators like Jonathan Barnes that think it is classifying predicates and not predications. 4) Kinds of predicates In his introduction of Categories, as J. W. Thorp truly points out , Aristotle distinguishes between the category of substance and the other categories using μὲν ... δὲ construction. This construction illustrates that beside tenfold classification of categories, there is an even more crucial differentiation between two kinds of predicates: substance or what is on the one hand and the other nine ones on the other hand: the distinction between what is predicated of the subject as what it is and what is predicated of it as an accident. Therefore, we have three kinds of classification - a twofold, a fourfold and a tenfold-complicatedly classifying the same thing, viz. the predicate. Predicates can be divided also to four kinds: property, definition, genus and accident. (To., I, 4, 101b11-20) A property is that predicate that is convertible with its subject and does not signify its essence. A definition is that predicate that is convertible with its subject and signifies its essence. It is a genus if it is not predicated convertibly and is contained in the definition of its subject. And it is an accident if it is neither convertible nor contained in the definition of its subject. (To., I, 8, ^103b3) All of these four kinds are among categories. (To., I, 9, 103b20) It seems that there might be some kind of relation between the twofold and the fourfold distinction: whereas genus and definition are predicated as what it is, accidents are not so predicated. There seems to be some rules that determine to each of these four kinds each predicate belongs. At To., IV, 123b30ff. Aristotle asserts: ‘If B has a contrary and A does not, then B does not belong to A as its genus.’ There is a dispute around per se accidents (τὰ καθ’ αὑτὰ συμβεβηκότα) (Topics., 102a18) whether they must be regarded as either of the four kinds or as a fifth kind. Barnes (1970) argued that they ‘do not fit at all neatly into the fourfold classification.’ He argues that based on the definition of accidents at A, 5, 102b4-5, they must be accidents but based on another definition, A, 5, 102b6-7, they cannot be accidents. He also defends the view that they are not properties. Barnes concludes: ‘This shows that the two definitions are not equivalent, and hence that the ‘predicables’ are not well-defined.’ Demetris J. Hadgopoulos defends the view that the two definitions of accidents are equivalent and per se accidents are properties. 5) Five types of predications We have five kinds of predications based on our division of subjects and our discussion of predicates: simple, primary (itself divided to substantial and accident), accidental (itself divided to primary and secondary), aoincidental and absolute predication. a) Simple predication. This is a predication in which a universal is predicated of either a particular or a universal subject. This sense of predication includes all other senses except the first kind of accidental predication. b) Primary predication. This is a predication in which a universal is predicated of a primary subject, namely a substance. A primary predication is of two kinds: i) Substantial predication. A primary predication in which the predicate is part of, or is included in, the definition of the subject. The universal that is the predicate here is the definition or the genus or the species or the diferentia of the subject. It is this predication that Aristotle calls a unity: ‘A statement may be called a unity … because it exhibits a single predicate as inhering not accidentally in a single subject.’ (PsA., B, 10, 93b35-37) It is only substantial predicates that can be predicated of each other: ‘Predicates which are not substantial are not predicated of one another.’ (PsA., A, 22, 83b18-19) Aristotle defines a substantial predication also in another way. A predication in which a higher genus is predicated on a lower genus, species, a substance or an individual, (or a species is predicated on an individual) is a substantial predication. Therefore, a substantial predication is a predication in a series that has individuals on one of its ends and a general category on its other end. In fact, only substantial predicates can be predicated of one another. (PsA., A, 22, 83b17-19) This series cannot be an infinite series because otherwise not only substances would not be definable but also a genus would be equal to one of its own species. (PsA., A, 22, 83b7-10) -/- ii) Accident predication. A primary predication in which the predicate is not part of, or is not included in, the definition of its subject. The universal that is the predicate here is the property or the accident of the subject. c) Accidental predication. This is a predication in which the subject is not a primary subject and its predicate is a substance. This predication is of two kinds: i) Primary accidental predication. This is a predication in which an accident is predicated of substance. Such a predication can go ad infinitum, which is inferable from Aristotle’s assertion that the secondary accidental predication cannot go ad infinitum. ii) Secondary accidental predication. It is a predication in which an accident is predicated of another accident. Such a predication, Aristotle asserts, cannot go ad infinitum because even more than two accidents cannot be combined. Now what is the meaning of Aristotle’s assertion that we cannot continue this ad infinitum? Does it mean that we cannot continue the predication ‘The musician is white’ and say ‘The white is Athenian?’ But why not? Or maybe he means that by adding any predication, we are still in a condition of predicating two accidents of a substance on each other. -/- As primary subjects, substances can also take the position of predicate though not essentially but accidentally. In propositions like ‘the white is a log’ or ‘That big thing is a log’ we observe substance taking the position of predicate but this is only accidentally: ‘When I affirm ‘the white is a log,’ I mean that something which happens to be white is a log- not that white is the subject in which log inheres (οὐχ ὡς τὸ ὑποκείμενον τῷ ξύλῳ τὸ λευκόν ἐστι), for it was not qua white or qua a species of white that the white (thing) came to be a log (οὔτε λευκὸν ὄν οὔθ᾿ ὃπερ λευκόν τι ἐγἐνετο ξύλον), and the white (thing) is consequently not a log except incidentally.’ (PsA., 22, 83a3-9) Aristotle compares this accidental use of substance in the position of predicate with the substantial use of it in the place of a subject: ‘On the other hand, when I affirm ‘the log is white,’ I do not mean that something else, which happens to be a log, is white (οὐχ ὃτι ἓτερόν τί ἐστι λευκόν, ἐκείνῳ δὲ συμβέβηκε ξύλῳ εἶναι), (as I should if I said ‘the musician is white,’ which would mean ‘The man who happens also to be a musician is white’); on the contrary, log is here the subject- the subject which actually came to be white, and did so qua wood or qua a species of wood and qua nothing else.’ (PsA., 22, 83a8-14) Aristotle asks us not to call propositions like ‘The white is a log’ a predication at all or at least call them accidental predication instead of simple (ἁπλως) predication. (PsA., A, 22, 83a14-17) An accidental predication, in which we have a substance in the place of predicate, is different from an essential predication in that while the subject of an accidental predication is said to be the predicate not by itself but as something different with which it coincides, the subject of an essential predicate is said to be the predicate by itself and not because it is something else: ‘Since there are attributes which are predicated of a subject essentially and not accidentally- not, that is, in the sense in which we say ‘That white (thing) is a man,’ which is not the same mode of predication as when we say ‘The man is white’: the man is white not because he is something else but because he is man, but the white is man because ‘being white’ coincides with ‘humanity’ within one subject. Therefore, there are terms such as are essentially subjects of predicates. (PsA., A, 19, 81a24-29) This capability of ‘non-essentially and only accidentally’ being a subject does belong, in fact, to all sensible things. (PsA., A, 27a32-36) d) Coincidental predication. this is a predication in which none of the subject and predicate are a substance or an individual. In this predication, one of the accidents of a substance or individual is predicated of one of the other accidentals of the same substance or individual. For example, when it is said that ‘The white is musical,’ there is an individual, say Socrates, for which both of white and musical are accidents. e) Absolute predication. This is a predication in which a form or a substance is predicated of a matter or a material substance. Some commentators like Loux and Lewis regarded this predication as close to accident predication, both based on inherence. As R.M. Dancy points out, these predications make Aristotle’s theory of predication immanentist: not only accident predications are explained by the immanence of accidents in substances, some of the substantial predications, which were not explained in Categories, are also explained by the immanence of form in matter. It is interesting that in this kind of predication, it is the predicate and not the subject, which is in the strictest sense substance. As the central books of Metaphysics claim, the form is the substance. Thus, in this predication, substance gets away from the sense of ὑποκείμενον. Corkum mentiones 68a19 as the only instance where Aristotle explicitly claims that a term may be predicated of itself, a passage that is, in Corkum’s view, problematic. 6) Demonstrable predicates Those predicates are demonstrable that are so related to their subjects that there are other predicates prior to them predicable of their subjects (ἔτι δ᾿ ἄλλος, εἰ ὧν πρότερα ἄττα κατηγορεῖται). (PsA., A, 22, 83b32-34) 7) Series of predications Since it is possible for a predicate to be itself the subject of another predication, we can have a series of predications in which the predicate of a predication is the subject of the next predication. This series has the following features: a) It has a limit (in number) (PsA., A, 22, 83b14-16) on the side of subjects: there are subjects that cannot themselves be predicated (PsA., A, 27, 43a39-41), which are, as we noted, prime subjects: particulars, i.e. prime substances and other individuals. (PsA., A, 19-22) Aristotle calls them ultimate (ὓστατον). (PsA., 21, 82a36-b1) b) It has a limit (in number of kinds) (PsA., A, 22, 83b14-16) also on the side of predicates: there must be predicates that cannot be subjects. (PsA., A, 19-22; PsA., A, 27, 43a36-39) Aristotle calls them primary (πρῶτον). (PsA., A, 21, 82b1-4) These are the highest categories or the highest genera of categories. (PsA., A, 22, 83b14-16) c) The series has an escalating shape from mere subjects at its downside to mere predicates at its upside. It is Aristotle himself whos uses the words up and down in this sense. (e.g. PsA., A, 22, 83b2-3) d) The predications that lie between lowest and highest ones must be finite in number. (PsA., A, 19-22 especially: 20, 82a21-35) These have subjects and predicates, each capable of both of the roles of being subject and being predicated. A result of this fitness is that neither demonstration can go to infinity nor everything is demonstrable, the two points Aristotle always insist on. e) The upward side includes the more universal ones and the downward the more particular ones. (PsA., 20, 82a21-23) f) It follows from the above features that ‘neither the ascending nor the descending series of predications … are infinite.’ (PsA., A, 22, 83b24-25) g) Reciprocation and convertibility. Except in case of terms (i.e. subjects and predicates) that are at each of the ends of series of predications, namely ultimates and primaries, it is possible to reciprocate (ἀντιστρέφειν) terms and convert the predication. (PsA., A, 19, 82a15-20) h) Antipredication. Antipredication means that in a predication (S is P), the subject becomes the predicate of its predicate (P is S) in the same category its predicate was predicated on it. For example, if P is in the category of quality, antipredication means that S be predicated of P in the category of quality. In other words, P is a quality of S and S is a quality of P. Aristotle rejects this. (PsA., A, 22, 83a36-b3) i) Self-predication versus other-predication. Aristotle distinguishes between a predication in which a term is said of itself and a predication in which a term is said of another. (Phy., Δ, 2, 209a31-33) j) Predicablity (Cat., 5, 3a36-b2): 1) Primary substances and individuals are not predicable. 2) Secondary substances are of two kinds: genus and species i) Genus is predicable able both of the species and of the individuals. ii) Species is predicable of the individual. 3) Differentiae are predicable both of the species and of the individuals. 8) Predication as classification a) Richard Patterson believes that Aristotle’s so repeated construction using hoper (estin A hoper B) in Topics (120a23 sq., 122b19, 26sq., 123a, 124a18, 125a29, 126a21, 128a35. Also in Posterior Analytics (83a24-30) (Brunschwig’s list. ‘expresses the fact that A is a kind of B (esti A B tis), that A is a species of the genus B.’ 9) Universal predication Aristotle defines universal predication (κατὰ παντὸς κατηγορεῖσθαι) as such: ‘wherever no instance of the subject (τῶν τοῦ ὑποκειμέμνου) can be found of which the other term cannot be asserted.’ (PrA., A, 24b27-29) In this predication, the subject is included in another as in a whole (ἐν ὃλῳ εἶναι) and the predicate is predicated of all of the subject (κατὰ παντὸς κατηγορεῖσθαι). (PrA., A, 24b26-27) Attach another discussion we had about ἐν ὃλῳ here. 10) Quantity of predication A predication, truly stated, has a quantity, which is the number of objects under the name of the subject of which the predicate is predicated. The quantity of subject can be stated in four ways: a. Indefinite: when the predicate belongs or does not belong to the subject without any mark to show to haw many of the particulars under the name of the subject it does or does not belong. E.g. ‘Man is white’; ‘Man is not white.’ (PrA., A, 24a20; OI., I, 7, 17b8-12) b. Universal quantity: When the predicate belongs to all or none of the subject. E.g. ‘Every man is animal’; ‘No man is animal.’ (PrA., A, 24a18-19; OI., I, 7, 17b5-6) The contrary of a predication of a universal quality is a predication of a universal quality. E.g. the contrary of ‘Every man is white’ is ‘No man is white.’ (OI., I, 7, 17b20-23) c. Particular quantity: When the predicate belongs (or does not belong) to some of the subject. E.g. ‘Some men are white’; ‘Some men are not white.’ (PrA., A, 24a19-20) d. Single quantity: when the subject is a proper name of only one object. E.g. ‘Socrates is white’; ‘Socrates is not white.’ The contrary of this predication is of a single quantity: ‘Socrates is not white.’ (OI., I, 7, 17b38-18a4) 11) Convertibility of predication. Some predications are convertible, that is, it is possible to change the place of subject and predicate in a true proposition so that the converted proposition remains true. This is supposed to mean that given the truth of a predication, the truth of the converted predication is inferable. The convert form of a predication depends on its quantity. a. Indefinite quantity: This predication has no strictly true convert because its quantity is not stated. b. Universal quantity: It can be converted in two ways: i) A negative universal can be converted to a negative universal in which the terms are changed. E.g. ‘No pleasure is good’ can be converted to ‘No good is pleasure.’ (PrA., A, 2, 25a5-8 and a14-19) ii) An affirmative universal can be converted to an affirmative particular in which the terms are changed. E.g. ‘Every pleasure is good’ can be converted to ‘Some good is pleasure.’ (PrA., A, 2, 25a7-9) c. Particular quantity: If it is negative, it cannot be converted but if it is affirmative, it can be converted to an affirmative predication with particular quantity. E.g. ‘Some pleasure is good’ can be converted to ‘Some good is pleasure.’ (PrA., A, 2, 25a10-13 and a20-24) d. Single quantity: It cannot be converted. 12) Characteristics of relations between subject and predicate 1. A predicate is of a wider range than its subject. It is based on this fact that Aristotle: a) Prevents individuals to be predicate because there is nothing of which an individual be of a wider range. In other words, it is due to the fact that since an individual is only ‘one particular’ thing and, thus, cannot be of a wider extent than anything that Aristotle prevents them of being a predicate. Matthews, however, thinks we cannot use Socrates, a substance and an individual, in the place of predicate and say it of Socrates because ‘Socrates does not classify Socrates: it names him.’ b) Prevents differentia, species and things under species to be predicated of genus. (To., Z, 6, 144a27-) c) Prevents the species and the things under it to be predicated of the differentia. (To., Z, 6, 144b1-4) d) Also about the effect because it is wider than its subject. (PsA., B, 17, 99a) e) Each attribute is wider than every individual it is predicated on, though several attributes, collectively considered, might not be wider but exactly the substance of a thing. (PsA., B, 13, 96a32-b1) 2. The predicate of a predicate of a subject will be predicated of the subject too: ‘whenever one thing is predicated of another as of a subject, all things said of what is predicated will be said of the subject too.’ (Cat., 3, 1b10-15) In fact, it is due to its predication of the subject that it is predicated of its predicate. (Cat., 5, 2a36-b1) Moreover, what is not predicated of the predicate of a subject cannot be predicated of it as well. (PrA., A, 27, 43b22-27) Thus, what, for example, is not predicated of animal, cannot be predicated of man. 3. The predicate of a subject can be predicated of its predicates as well. (Cat., 5, 3a1-6) For example, you call the individual man grammatical and, thence, you call both a man and an animal grammatical. Nonetheless, the predicate of a subject belongs to it more properly than to its higher predicates. (PrA., A, 27, 43a27-32) 4. It is only the subject that can be distributed and not the predicate. (PrA., A, 27, 43b16-22; OI, I, 7, 17b12-16) Therefore, we can say e.g. ‘Every man is animal’ but we cannot say ‘Every man is every animal.’ 5. It is the reason of the relation between subjects and predicates, that is the reason of predication, which is the subject of inquiry. (Met., Z, 1041a20-24) In other words, since it is a meaningless inquiry to ask why a thing is itself (Met., Z, 1041a14-15), the only remaining meaningful inquiry is to ask why something is something else, i.e. to ask about the reason of predication. 6. A subject cannot categorize its predicate in the same category in which it is categorized by it. If e.g. A is a quality of B, B cannot be a quality of A. Therefore, there is no reciprocation in the same category. (PsA., A, 22, 83a36-39) 13) Characteristics of series of predications 1. A series of secondary accidental predication cannot go ad infinitum for not even more than two terms can be comnbined. For an accident is not an accident of an accident, unless it be because both are accidents of the same subject. (Met., Γ, 1007b1-4) 2. Infinite series cannot be traversed in thought. (PsA., A, 22, 83b6-7) 3. The predications of genera on each other must be ended and cannot go to infinity because otherwise not only substances would not be definable but also a genus would be equal to one of its own species. (PsA., A, 22, 83b7-10) Therefore, a series of predication of genera on each other must be limited on both sides. There must be an upward limit in general categories as well as a downward limit in individual because they cannot be predicated of others. Whatever lies between these limits can both be predicated of others and others be predicated of them. (PrA., A, 27, 43a36-43) 4. The order of predicates matters: it makes a difference whether the series be ABC or BAC. (PsA., B, 13, 96b25-32) . (shrink)

GAMETOGÊNESE -/- Emanuel Isaque Cordeiro da Silva Instituto Agronômico de Pernambuco Departamento de Zootecnia – UFRPE Embrapa Semiárido -/- • _____OBJETIVO -/- Os estudantes bem informados, estão a buscando conhecimento a todo momento. O estudante de Veterinária e Zootecnia, sabe que a Reprodução é uma área de primordial importância para sua carreira. Logo, o conhecimento da mesma torna-se indispensável. No primeiro trabalho da série fisiologia reprodutiva dos animais domésticos, foi abordado de forma clara, didática e objetiva os mecanismos de diferenciação (...) sexual dos embriões em desenvolvimento, quais os genes envolvidos nesse processo e tudo mais. Nesse segundo trabalho, a abordagem será teórica, mas também clara, sobre a formação primordial dos gametas femininos e masculinos, através da ovogênese nas fêmeas e a espermatogênese nos machos. Esse trabalho visa levar a importância do processo de formação dos gametas e a produção hormonal das gônadas, bem como o entendimento sobre as interações com o eixo hipotálamo-hipofisário. -/- •____INTRODUÇÃO -/- A reprodução sexual é um processo mediante a qual dois organismos da mesma espécie unem seu material genético para dar lugar a um organismo fixo com combinação única de genes; para isso, cada organismo produz células que contém a metade do material genético característico da espécie. Essas células haploides (1n) são denominadas gametas; ao combinar-se um gameta masculino com um feminino produz-se uma célula diploide (2n) (zigoto ou ovo) a partir da qual se forma o embrião. A grande maioria das espécies com reprodução sexual são anisogâmicas, o que significa que produzem dois tipos de gametas diferentes: os gametas masculinos são microscópios, móveis e produzem-se em grande quantidade, enquanto que os femininos são grandes, imóveis e produzem-se em menor quantidade. O tipo de gameta que um indivíduo produz é o que define seu sexo; sobre os animais o macho é o indivíduo que produz grandes quantidades de espermatozoides e a fêmea produz uma menor quantidade de óvulos, enquanto que nas plantas as gônadas masculinas são as produtoras pólen e as femininas produzem oosferas. Os gametas são diferentes do resto das células do organismo, as quais se chamam células somáticas; essas últimas são diploides porque contém dois pares de cromossomos, um par herdado do pai do indivíduo e o outro da mãe. As células somáticas, ademais, se dividem por mitose, ao qual os cromossomos se duplicam antes de cada divisão celular e cada uma das células filhas recebe um complemento diploide idêntico dos cromossomos, logo todas as células somáticas de um indivíduo possuem o mesmo material genético, embora cada tipo celular expresse diferentes combinações de genes. Em contraponto, os gametas são células haploides porque possuem somente um par de cromossomos e a metade do material genético característico da espécie. Cada um dos cromossomos em um gameta é resultado da recombinação dos genes contidos nos cromossomos paterno e materno do indivíduo que originam o gameta, e cada um destes possuem uma combinação única de genes. Os gametas se formam a partir das células germinais, que são células que em sua origem são diploides e elas de “comprometem” a manter-se como uma linha celular especial que em determinado momento sofrerá o processo de meiose para dar origem aos gametas haploides, sejam óvulos ou espermatozoides segundo o sexo do animal. Como descrito no trabalho sobre a diferenciação sexual, as células germinativas primordiais originam-se no epiblasto do embrião, e migram desde o saco vitelino até colonizar as cristas gonodais, onde, por sua vez, proliferam-se e se organizam junto com as células somáticas da gônada primitiva para formar o testículo ou o ovário. As células germinais masculinas e femininas tem a mesma origem embrionária. As gônadas indiferenciadas em um embrião possuem três tipos celulares: as células que dão origem aos gametas (ovogonia ou espermatogonia), as precursoras de células que nutrem os gametas em desenvolvimento (células da granulosa no ovário; células de Sertoli no testículo) e as precursoras de células que secretam hormônios sexuais (células da teca no ovário; células de Leydig no testículo). As células germinais são as únicas estruturas do organismo que têm a capacidade de dividir-se por meiose sofrendo uma redução no número de seus cromossomos, sendo responsável pela transmissão da carga genética aos descendentes. Em contraste, as células somáticas somente se dividem por mitose. A formação dos gametas compreende fases sequenciais de mitose, meiose e pós-meiose. Esses processos são altamente organizados e necessitam de um preciso e bem coordenado programa de expressão genética. Uma das características importantes da gametogênese é a redução cromossômica, que através da meiose, reduz pela metade o número de cromossomos e produz células distintas entre si, devido a trocas de material genético entre os pares de cromossomos provenientes do pai e da mãe, o que ocorre no processo de “crossing over” durante a primeira fase da meiose. A gametogênese é o processo mediante o qual as células germinais de cada sexo se multiplicam, dividem e diferenciam até formar os gametas. No caso da formação dos gametas masculinos o processo recebe o nome específico de espermatogênese, e para os gametas femininos é denominado como ovogênese. Embora os dois processos alcancem o objetivo comum de produção das células haploides, por onde compartilham algumas características, existem diferenças marcadas entre eles devido a necessidade de produzir um número muito distinto de gametas, de tamanho diferente, e com características de motilidade também distintas. -/- •___ESPERMATOGÊNESE -/- A espermatogênese é o processo mediante o qual se produz os gametas masculinos denominados espermatozoides. Durante a vida fetal as células germinais e as células somáticas do testículo em formação organizam-se em túbulos seminíferos que se derivam dos cordões sexuais primários e conformam a maior parte da medula do testículo. Na etapa fetal cada tubo seminífero é delimitado por uma membrana basal, recoberta na parte interior pelas células precursoras das células de Sertoli (um tipo de células somáticas). No exterior do túbulo localizam-se as células precursoras das células de Leydig ou intersticiais (figura 1), que também são células somáticas. Entre a membrana basal e as células de Sertoli encontram-se algumas células germinais denominadas espermatogonias de reserva A0 (denominadas gonócitos) que serão o único tipo de células germinais presentes no testículo enquanto o animal não alcançar a puberdade. As células de Sertoli estabelecem na região basal uniões oclusoras entre si, formando parte da barreira hemato-testicular. As espermatogonias A0 localizam-se por dentro da membrana basal do túbulo seminífero, embora fora da barreira hemato-testicular. Figura 1: fase neonatal. Nota-se a grande infiltração de tecido intersticial em quase 50% da seção originando que os túbulos sejam pequenos e redondos em sua maioria. O citoplasma e núcleo das células pré-Leydig são notadas claramente por essa ser uma espécie suína onde o tecido intersticial está claramente diferenciado. Hematoxilina-eosina (X 220.5). Fonte: Embrapa. -/- O número de células de Sertoli no testículo depende da influência do hormônio folículo estimulante (FSH) presente durante a vida fetal e as primeiras etapas de vida pós-natal. A população de células de Sertoli ao chegar a puberdade se manterá fixa durante o resto da vida do animal; existe uma relação positiva entre o tamanho e a população de células de Sertoli e a capacidade de produção de espermatozoides do testículo. As células de Sertoli são as únicas células somáticas que estão no epitélio seminífero, e sua função é a nutrição, sustentação e controle endócrino das células germinais. As células de Sertoli participam ativamente no processo de liberação dos espermatozoides para a luz do túbulo. Nesse momento, as células de Sertoli realizam a fagocitose de parte do citoplasma do espermatozoide dos chamados corpos residuais. As células de Sertoli também fagocitam as células germinais que se degeneram no curso normal da espermatogênese. Essas células ainda sintetizam grande quantidade de proteínas, como por exemplo as proteínas ABP (androgen hinding protein), que transportam andrógenos para todo o aparelho reprodutivo, transferrinas, que transportam ferro para a respiração celular das células germinais e também às inibinas, que regulam a liberação de FSH pela hipófise, através de um sistema de retroalimentação (feedback) negativa (figura 2). Figura 2: epitélio seminífero, células de Sertoli (flecha) (400 X). Fonte: Embrapa. -/- Antes da puberdade dos túbulos seminíferos observam-se ao corte como estruturas de diâmetro pequeno, sem luz, e conformados unicamente pelas células de Sertoli e espermatogonias de reserva e rodeados por abundante tecido intersticial, ao que estão presentes as células precursoras das células de Leydig. Ainda antes da puberdade, a diferenciação celular manifesta-se primeiro pela presença de espermatócitos primários, os quais se degeneram em geral na fase de paquíteno, por falta de estimulação hormonal. A partir de que o animal chega a puberdade inicia-se o processo de espermatogênese, que se manterá durante toda a vida do animal, exceto em espécies de animais silvestres muito estacionais, ao qual pode se suspender durante a época não reprodutiva para voltar e ser retomada na época ou estação reprodutiva. Depois da puberdade, os túbulos seminíferos possuem um diâmetro muito maior; em seu interior observa-se um grande número de células germinais de todos os tipos, diferentes estádios de divisão, e em seu lúmen contém líquido e espermatozoides. Ainda sobre o alcancei da puberdade, as espermatogonias começam a dividir-se aceleradamente por mitose, enquanto que no espaço intersticial as células mesenquimais também começam a se diferenciar e a dar origem as células de Leydig (figura 3). A partir dessa etapa as células de Leydig (totalmente diferenciadas) são também evidentes no exterior do túbulo, junto com as células mioides ou peritubulares que o rodeiam o que ao contrair-se são responsáveis por controlar o avanço dos fluidos e as células presentes no lúmen do túbulo. As células mioides estão situadas ao redor do túbulo, e é creditado a elas a promoção da contração e da integridade estrutural do túbulo. Esse tipo celular apenas se diferencia na puberdade pela ação dos andrógenos (figura 4). As interações entre as células de Sertoli e as mioides parecem ter um papel importante na manutenção das funções do testículo. Durante o processo de espermatogênese, as espermatogonias de reserva dividem-se periodicamente e enquanto algumas células fixas permanecem como espermatogonias de reserva, outras proliferam e sofrem uma seção de divisões mitóticas durante as quais se vão diferenciando até formarem espermatócitos primários (espermatocitogênese ou fase de mitose), logo sofrem divisões especiais mediante as quais reduzem seu número de cromossomos (fase de meiose), e ao final trocam de forma para converter-se em espermatozoides (espermatocitogênese) (figura 5). Cada uma dessas etapas da espermato- gênese será descrito detalhadamente adiante, antes é necessário a explicação de algumas características das células de Sertoli e de Leydig que ajudarão a entender seu papel durante a espermatogênese. Figura 3: células de Leydig no espaço intersticial do testículo bovino adulto PAS (400 X). Fonte: Embrapa. -/- Figura 4: o estabelecimento da puberdade pela presença de espermatozoides no túbulo. Hematoxilina-eosina (400 X). Fonte: Embrapa. Figura 5: fases mitóticas das espermatogonias (A0 e B) para formação de um espermatócito primário e as duas fases de meiose que se sucedem antes da espermatogênese. Fonte: ZARCO, 2018. -/- Ao início da espermatocitogênese as uniões oclusoras entre as células de Sertoli se abrem por etapas (como as comportas de um submarino) para permitir a passagem das espermatogonias em direção ao centro do túbulo seminífero sem que se estabeleça uma continuidade entre o exterior e o interior da barreira hemato-testicular. Uma vez ultrapassada essa barreira, as sucessivas gerações de espermatogonias, espermatócitos, espermátides e espermatozoides irão se localizar em direção ao interior do túbulo seminífero, em estreita associação com as células de Sertoli. Em consequência, as células de Sertoli dividem o túbulo seminífero em dois compartimentos; o compartimento basal (debaixo das uniões oclusoras das células de Sertoli), ao qual residem as espermatogonias de reserva, e o compartimento adluminal (em direção ao centro do túbulo), cujos espaços entre as células de Sertoli desenvolvem o resto do processo de espermatogênese (meiose e espermatocitogênese). Esse feito é importante porque durante a vida fetal as únicas células germinais existentes eram as espermatogonias de reserva, pelo que os antígenos expressados por gerações mais avançadas (espermatogonias intermediárias, secundárias, espermátides e espermatozoides) não são reconhecidos como próprios do corpo pelo sistema imunológico. Logo, o anterior implica que deve existir uma barreira entre eles e o sangue para evitar um ataque imunológico. Em todas as etapas da espermatogênese, as células de Sertoli atuam como células de suporte para as células germinais, que sempre permanecem recoberta pela membrana das células de Sertoli. Também atuam como células nutricionais já que proporcionam o meio em que as células germinais se desenvolvem e maturam, assim como as substâncias que regulam e sincronizam as sucessivas divisões e transformações das células germinais. As células de Sertoli produzem hormônios, como estrógenos e inibina que atuam sobre a hipófise para regular a secreção das gonadotropinas que controlam a espermatogênese. As células de Leydig que residem no exterior do túbulo seminífero também são importantes para a espermatogênese: produzem a testosterona que estimula e mantém a espermatogênese, bem como serve como substrato sobre o qual atua como aromatizador das células de Sertoli para transformá-las em estrógenos. Como supracitado, para seu estudo podemos dividir a espermatogênese em três fase: espermatocitogênese, meiose e espermiogênese (figura 6). Agora, serão descritas cada uma dessas etapas. Em algumas espécies, incluindo no homem, os macrófagos representam o segundo tipo celular intersticial mais numeroso no testículo, depois das células de Leydig. Os macrófagos e vários subtipos de linfócitos são identificados nós testículos de ovinos e ratos. Eles estão intimamente associados com as células de Leydig e atuam juntamente na regulação da esteroidogênese. Figura 6: fluxograma da espermatogênese. -/- Espermatocitogênese -/- A espermatocitogênese, também chamada de etapa proliferativa ou de mitose, consiste numa série de divisões mitóticas sofridas pelas células descendentes de uma espermatogonia de reserva. Uma vez que a célula se divide, abandona o estado de reserva e começa um processo de diferenciação. As espermatogonias de reserva (denominadas espermatogonias A0 na rata ou As nos humanos) são células que existem desde a vida fetal e que permanecem mitoticamente inativas durante a infância. Uma vez que alcançam a puberdade começam a dividir-se em intervalos regulares, e as células filhas podem permanecer como espermatogonias de reserva ou abandonar a reserva e ingressar na dita espermatocitogênese. Uma vez abandonada a reserva, as células filhas que vão se formando em cada divisão permanecem unidas por pontes citoplasmáticas, constituindo um clone que se divide sincronicamente. As células que se formam depois de cada divisão continuam sendo espermatogonias, porém cada geração é ligeiramente diferente da anterior. Na rata, por exemplo, as espermatogonias tipo A0 ao dividir-se originam espermatogonias do tipo A1, que em sucessivas divisões formam espermatogonias dos tipos A2, A3 e A4, as quais, por sua vez, sofrem outra mitose para formar espermatogonias intermediárias e uma mais para formar espermatogonias do tipo B. Essas últimas se diferenciam (sem se dividir) em espermatócitos primários, processo em que termina a fase de espermatocitogênese, que literalmente significa processo de geração de espermatócitos. As espermatogonias tipo A0 são a fonte para a contínua produção de gametas. A metade delas se dividem e formam células iguais (as chamadas células tronco) e a outra metade forma as espermatogonias A1, que sofre novas divisões mitóticas e formam os tipos 2, 3 e 4. O tipo A4 sofre mitose para formar a intermediária (A In), que por mitose, forma a tipo B (figura 6). Esses tipos de espermatogonias podem ser identificadas em evoluções histológicas de acordo com sua organização topográfica na membrana basal dos túbulos seminíferos ou mediante seu conteúdo de heterocromatina. Outra maneira de diferenciação se baseia em marcadores moleculares específicos que distinguem as espermatogonias tronco (A0) das demais, com os fins de isolamento, desenvolvimento in vitro e transplante. As tipo B passam por mitose para formarem os espermatócitos primários; estes iniciam a primeira etapa da meiose formando os espermatócitos secundários; na segunda etapa da divisão meiótica, cada espermatócito secundário se divide e formam as chamadas espermátides. Quando o testículo alcança seu desenvolvimento total, a meiose completa-se e as espermátides originadas se convertem em espermatozoides. Um dos maiores sinais característicos desse fenômeno é o alargamento das espermátides e sua migração em direção ao lúmen do túbulo seminífero (figuras 4, 7 e 8). Figura 7: espermatogonias marcadas por imuno-histoquímica, anticorpo monoclonal TGFa (400 x). Figura 8: fases de divisões meióticas (M), espermatócitos em paquíteno (PA) e espermatócitos secundários (ES). -/- Figura 9: estádio posterior a liberação dos espermatozoides na luz do túbulo. Hematoxilina-eosina (400 x). Mediante as seis divisões mitóticas que ocorrem durante a espermatocitogênese se forma potencialmente um clone de 64 espermatócitos primários a partir de cada espermatogonia A que ingressa sobre o processo. Não obstante, algumas células sofrem apoptose em cada uma das etapas do processo, ao qual o número real formado é menor. Em outras espécies produzem-se um transcurso similar de divisões mitóticas sucessivas durante a espermatocitogênese, embora a nomenclatura utilizada possa ser distinta, por exemplo nos bovinos as duas últimas divisões mitóticas dão origem as espermatogonias de tipo B1 e B2. -/- Meiose -/- Uma vez que as espermatogonias B se diferenciam em espermatócitos primários, esses iniciam a etapa de meiose, com uma nova divisão; desta vez a divisão é do tipo meiótica. Ao completar-se a primeira divisão meiótica (meiose I) se obtém os espermató-citos secundários, que ao sofrer a segunda divisão meiótica (meiose II) dão origem as espermátides. Vale salientar que a meiose é o processo mediante o qual reduz-se a metade do número de cromossomos, pelo que as espermátides que se obtém são células haploides (1n). Os espermatócitos secundários que se formam depois da primeira divisão meiótica contém a metade do número normal de cromossomos, porém a mesma quantidade de DNA já que cada cromossomo é duplo. As espermátides formadas na conclusão da segunda divisão meiótica (figura 7), por sua vez, contém a metade dos cromossomos, e esse já não são duplos, já que se trata de células 1n. Também deve-se enfatizar que durante a meiose é relevante o entrecruzamento dos cromossomos homólogos, pelo que cada espermátide possui uma combinação única e diferente de genes paternos e maternos. Outro ponto que deve ser levado em consideração é que cada espermátide somente possui um cromossomo sexual; a metade das espermátides contém o cromossomo X herdado da mãe do macho que está levando a cabo a espermatogênese e a outra metade contém o cromossomo Y herdado de seu pai. Para cada espermatócito primário que entra no processo de meiose obtém-se cerca de quatro espermátides, pelo qual ao ser completada a meiose potencialmente se poderiam formar até 256 espermátides por cada espermatogonia que abandona a reserva e ingressa na espermatocitogênese. -/- Espermiogênese -/- Durante a espermiogênese, também chamada de fase de diferenciação, as esper-mátides sofrem, sem se dividir, uma metamorfose que as transforma em espermatozoides, os quais finalmente são liberados das células de Sertoli em direção ao lúmen do túbulo seminífero. A espermiogênese é um processo complicado e longo já que a espermátide deve sofrer complexas trocas nucleares, citoplasmáticas e morfológicas que resultam na forma-ção dos espermatozoides. Algumas dessas mudanças incluem a condensação do material nuclear para formação de um núcleo plano e denso, a eliminação do citoplasma para a constituição de uma célula pequena, a formação de uma estrutura especializada denomi-nada acrossomo ou tampa cefálica, e a formação do pescoço e da cauda (flagelo) do esper-matozoide, do que depende a sua motilidade. Durante a maior parte da espermiogênese, as espermátides se mantém com uma estreita associação com as células de Sertoli; logo, chega-se a observar, então, flagelos que se projetam em direção a luz do túbulo que pare-cem sair das células de Sertoli, sendo na realidade os flagelos dos espermatozoides que ainda não tinham sido liberados pelo lúmen. Ao liberar os espermatozoides em direção a luz do túbulo, as células de Sertoli realizam a fagocitose de parte do citoplasma dos espermatozoides (corpos residuais). Também fagocitam os restos de todas as células germinais que sofrem apoptose ou degeneram-se durante a espermatogênese. Credita-se que ao realizar essas funções as células de Sertoli podem fazer uma monitoração eficiente da espermatogênese, o que lhes permitiria emitir sinais para colaborar na regulação desse processo em nível gonodal e a nível sistêmico através da secreção de hormônios como a inibina e o estradiol. Além da inibina e activina, as células de Sertoli sintetizam outras proteínas, como a ABP (proteína ligadora de andrógenos) que serve como uma molécula de transporte de andrógenos dentro dos túbulos seminíferos, ductos deferentes e epidídimo, ou a transfer-rina, que transporta o ferro necessário para a respiração celular. -/- Resultados da espermatogênese -/- O resultado da espermatogênese não significa apenas uma simples multiplicação das células germinais (até 256 espermatozoides a partir de cada espermatogonia A1), senão que através dela são produzidos gametas haploides pequenos, móveis e com grande diversidade genética entre eles, ao mesmo tempo que se mantêm uma reversa de células mãe (espermatogonias A0) a partir das quais se poderiam originar novos ciclos de esper-matogênese durante o resto da vida do animal. -/- Controle hormonal da espermatogênese -/- Como mencionado, o FSH reproduz um importante papel para o estabelecimento das células de Sertoli durante a vida fetal e início da vida pós-natal. O começo da esper-matogênese também é estimulado pelo FSH, que atua sobre as células de Sertoli para estimular sua função e a ativação de sinais dessas células em direção as células germinais, incluindo-as a abandonar a reserva e ingressar na espermatogênese. O FSH, assim mesmo, estimula a mitose durante o resto da espermatogênese e aumenta a eficiência do processo, já que reduz a apoptose e a degeneração de espermatogonias intermediárias e do tipo B. O FSH também estimula as células de Sertoli para produzirem inibina e ABP. Uma vez iniciada a espermatogênese somente requerem níveis baixos de FSH para se mantê-la. As células de Sertoli também devem ser estimuladas pela testosterona para funcio-nar de maneira adequada; se requer também do LH hipofisário: hormônio que estimula as células de Leydig para produzir testosterona. Por sua vez, a secreção de LH e FSH é regulada pelo GnRH hipotalâmico: esse neurohormônio também faz parte do mecanismo de regulação da espermatogênese. A espermatogênese também é modulada em nível local mediante a produção de determinados fatores e interações entre as células. Dentro dos fatores locais podemos mencionar o fator de crescimento parecido com a insulina 1 (IGF-1), o fator de crescimen-to transformante beta (TGF- β), activina, ocitocina e diversas citocinas. Entre as intera-ções celulares existem tanto uniões de comunicação entre as células de Sertoli e as células germinais, como pontes citoplasmáticas entre todas as células germinais que formam o clone de células descendentes de uma espermatogonia A1. Uma vez que as células de Sertoli iniciam sua função na puberdade é possível manter experimentalmente a espermatogênese somente com testosterona, sem ser requeri-dos nenhum outro hormônio. A quantidade de espermatozoides produzidos, no entanto, é maior quando há presença do FSH. Abaixo do estímulo do FSH as células de Sertoli produzem estradiol e inibina, hormônios que geram uma retroalimentação sobre o eixo hipotálamo-hipofisário para a regulação da secreção de gonadotropinas. Em particular, a inibina reduz a secreção de FSH, pelo qual é factível que sirva como um sinal que evite uma excessiva estimulação as células de Sertoli. -/- Ciclo do epitélio seminífero -/- Em cada espécie as espermatogonias de reserva iniciam um novo processo de divi-sões celulares em intervalos fixos: a casa 14 dias no touro; 12 dias no garanhão e a cada 9 dias no cachaço (reprodutor suíno). A nova geração de células que começam a proliferar sobre a base do tubo deslocam-se em direção ao centro do túbulo a geração anterior, que por sua vez deslocam-se as gerações anteriores. Devido as mudanças que vão sofrendo cada geração celular se ajustam a tempos característicos de cada etapa, já que rodas as células em uma determinada seção do túbulo estão sincronizadas entre si pelas células de Sertoli; em cada espécie somente é possível encontrar um certo número de combinações celulares: 14 diferentes combinações no caso da rata, 8 no touro e 6 no ser humano. A sucessão de possíveis combinações até regressar a primeira combinação se conhece como o ciclo do epitélio seminífero. Na maioria das espécies os espermatozoides que são libera-dos em direção a luz do túbulo provém das células que entraram no processo de esperma-togênese quatro gerações antes que a geração que está ingressando nesse momento, pelo que a espermatogênese no touro dura ao redor de 60 dias e um pouco menos em outras espécies domésticas. Significa que os efeitos negativos das alterações na espermatogêne-se podem estar presentes até dois meses depois de que se produziram essas alterações. Como supracitado, geralmente se observa a mesma combinação celular em toda a área de uma determinada secção transversal do túbulo seminífero. No entanto, se fizermos uma série de secções, observa-se que ao longo do túbulo há uma sucessão ordenada de combinações (a primeira em uma determinada secção; a segunda combinação na seguinte secção, e assim sucessivamente em secções subsequentes até regressar a primeira combi-nação. Teremos, então, que ao início da divisão das espermatogonias A1 se produz de forma sincronizada em uma secção do túbulo, e vai-se transmitindo como uma onda peristáltica as secções adjacentes. Esse processo é denominado como onda do epitélio seminífero e graças à esse túbulo seminífero sempre tem secções em todas as etapas da espermatogênese, com o que se alcança uma produção constante de espermatozoides. -/- Alterações da espermatogênese -/- Nas espécies estacionais a espermatogênese, como já mencionado, pode reduzir-se ou inclusive suspender sua atividade fisiológica durante a época não reprodutiva dessas espécimes, porém esse processo fisiológico não pode ser considerado como uma altera-ção. No entanto, a espermatogênese só pode ser alterada pelas enfermidades ou por fatores externos. A principal causa de alterações na espermatogênese é o aumento da temperatura testicular. Por isso, os testículos são localizados na saco escrotal e são “caídos” para fora do corpo como pode-se observar nos bovinos, caprinos, ovinos, caninos e no próprio homem. A temperatura testicular deve estar cerca de 2 a 6 °C abaixo da temperatura corporal normal. As células germinais masculinas são sensíveis ao calor, pelo qual na maioria dos mamíferos os testículos se encontram fora da cavidade abdominal e existe um sofisticado sistema de termorregulação para mantê-los a uma temperatura menor que a corporal. Se a temperatura corporal for elevada ou se os testículos permanecerem na cavidade abdominal, ou ainda se os sistemas termorreguladores do testículo sejam afetados por fatores inflamatórios como edema ou falta de mobilidade testicular dentro do escroto, a temperatura do tecido testicular aumentará e a espermatogênese sofrerá alterações proporcionais ao excesso de temperatura e a duração da elevação. A espermatogênese também pode ser afetada pela exposição a hormônios ou a outras substâncias. É possível que a causa mais comum (sobretudo no homem) seja o uso de esteroides anabólicos, que elevam a concentração de andrógenos na circulação, provo-cando um feedback negativo sobre a secreção de gonadotropinas. Ao deixar de estimular-se o testículo pelas gonadotropinas, este deixará de produzir testosterona, e as concentra-ções de andrógeno exógeno nunca alcançará as altíssimas concentrações de testosterona que normalmente estão presentes a nível do tecido testicular por ser o local onde se produz o hormônio. Também se supõe que diversas substâncias com propriedades estrogênicas derivadas de processos industriais (indústria dos plásticos, hidrocarbonetos etc.) e presentes no ambiente (fatores xenobióticos) podem ser responsáveis pelas alterações na espermatogênese em diversas espécies, entre as quais se inclui o ser humano. -/- • OVOGÊNESE E FOLICULOGÊNESE -/- A ovogênese é o processo seguido pelas células germinais da fêmea para a forma-ção dos óvulos, que são células haploides. Durante a vida fetal as células germinais proliferam-se no ovário por mitose, formando um grande número de ovogonias, algumas das quais se diferenciam em ovócitos primários que iniciam sua primeira divisão meiótica para deter-se na prófase da divisão. Somente alguns desses ovócitos primários retornarão e concluirão a primeira divisão meiótica em algum momento da vida adulta do animal, dando origem a um ovócito secundário e a um corpo polar. O ovócito secundário inicia a sua segunda divisão meiótica, a qual volta a ficar suspensa até receber um estímulo apropriado, já que somente os ovócitos secundários que são ovulados e penetrados por um espermatozoide retornam e concluem a segunda divisão meiótica, dando origem a um óvulo (figura 10). O processo de ovogênese é realizado dentro dos folículos ovarianos, que também tem que sofrer um longo transcurso de desenvolvimento e diferenciação denominado foliculogênese pelo que a ovogênese como tal realiza-se dentro do marco desse último processo. Por essa razão, na seguinte seção descreverei tanto a ovogênese como a folicu-logênese, e a relação que existe entre ambos. Figura 10: representação da ovogênese. Na etapa de proliferação, as células germinais se diferen-ciam por mitose. A meiose I se caracteriza por uma prófase prolongada, ocorrendo a duplicação do DNA. Nas duas divisões, que ocorrem antes da ovulação e depois da fertilização, a quantidade de DNA é reduzida a 1n, com o fim de que a fusão dos pronúcles (singamia) pós-fertilização, seja gerado um zigoto com um número de cromossomos de 2n (diploide). -/- Geração de ovócitos primários e folículos primordiais Tanto a ovogênese como a foliculogênese iniciam-se durante a vida fetal, quando as células germinais primordiais provenientes do saco vitelino colonizam a gônada primitiva e, junto com as células somáticas z organizam-se para a formação dos cordões sexuais secundários, que se desenvolvem principalmente no córtex do ovário. Nesse período, as células germinais que colonizaram o ovário sofrem até 30 divisões mitóticas, proliferando-se até formar milhares ou milhões de ovogonias, que inicialmente formam “ninhos” constituídos cada um deles por um clone de várias ovogonias que descendem da mesma célula precursora e que se mantêm unidas por pontes citoplasmáticas, sincronizan-do suas divisões mitóticas. Nessa etapa alcança-se a máxima população de células germinais no ovário, que antes de nascer se reduzirá drasticamente por apoptose. No ovário do feto humano chegam a haver até sete milhões de células germinais que ao nascimento se reduzem a dois milhões. Os ovários fetais do bovino, de maneira análoga, chegam a ter até 2.100.000 células germinais, que ao nascimento reduzem para 130.000 aproximadamente. A redução no número de ovogonias produz-se ao mesmo tempo que essas células, que vêm dividindo-se por mitose e estão agrupadas em ninhos, iniciam sua primeira divisão meiótica para se transformarem em ovócitos primários: células germinais que se encontram em uma etapa de suspensão (diplóteno) da prófase da primeira divisão meiótica. Nesse período produz-se uma grande proporção de células germinais; as células somáticas dos cordões sexuais, por sua vez, emitem projeções citoplasmáticas que separam a isolam os ovócitos primários sobreviventes, ficando cada um deles rodeados por uma capa de células aplanadas da (pré) granulosa. Ao mesmo tempo em que se forma uma membrana basal entre as células da granulosa e o tecido intersticial do ovário. Ao ovócito primário rodeado de uma capa de células da (pré) granulosa aplanadas e delimita-das por uma membrana basal denomina-se de folículo primordial (figura 11). Nas vacas os folículos primordiais bem formados já estão presentes nos ovários a partir do dia 90 da gestação. A maioria dos folículos primordiais com os que nasce uma fêmea se manterão inativos durante um longo tempo; muitos deles durante toda a vida do animal. Nos folículos primordiais inativos tanto os ovócitos primários como as células da granulosa conservam sua forma original e mantém um metabolismo reduzido estritamente ao mínimo necessário para manter-se viáveis. Por essa razão, ao realizar um corte histológico de qualquer ovário as estruturas mais numerosas que se observam serão os folículos primordiais. No entanto, cada dia da vida de um animal, inclusive desde a vida fetal, um certo número de folículos primordiais reiniciam seu desenvolvimento, e a partir desse momento um folículo exclusivamente pode ter dois destinos: o primeiro, prosseguir seu desenvolvi-mento até chegar a ovular, e o segundo (que é muito mais frequente) encontrar em algum momento condições inadequadas que fazem fronteira com ele para parar seu desenvolvi-mento, levando-o a sofrer atresia e degenerar até desaparecer do ovário. Figura 11: sequência da foliculogênese apresentando as diferentes estruturas que podemos encontrar em cada fase. Fonte: ZARCO, 2018. Culminação da ovogênese A ovogênese somente se completará quando um ovócito primário reinicia a meio-se; completa sua primeira divisão meiótica para formar um ovócito secundário e um primeiro corpo polar e, quando, finalmente sofrer uma segunda divisão meiótica para formar um óvulo e um segundo corpo polar. Os óvulos são as células 1n que constituem os gametas femininos, pouco numerosos, grandes e imóveis. A grande maioria dos ovóci-tos primários, como veremos mais adiante, nunca retomam a meiose e, em consequência, não chegam a formar ovócitos secundários, e muitos dos ovócitos secundários tampouco sofrem uma segunda divisão meiótica, pelo que não chegam a formar os óvulos. Ao longo da vida de uma fêmea, na maioria das espécies, menos de 0,1% dos ovócitos primários (um a cada mil) chega a terminar a ovogênese, dando origem a um óvulo. O supracitado deve-se a que a ovogênese somente pode retomar-se e ser completa-da em ovócitos primários que se encontram dentro dos folículos primordiais que (uma vez ativados) vão alcançando diversas etapas de seu desenvolvimento em momentos precisos aos que encontram as condições ideais de oxigenação, nutrição, vascularização e exposição a fatores parácrinos e a exposição a concentrações de hormônios que se requerem para que o folículo continue em cada etapa de seu desenvolvimento com o processo de foliculogênese até chegar a ovular. Qualquer folículo que não esteja nessas condições ao longo do desenvolvimento sofrerá degeneração e atresia, pelo que o ovócito primário em seu interior nunca chegará ao ponto em que pode retomar a primeira divisão meiótica. No que resta da presente seção revisaremos o processo de foliculogênese em cujo marco se desenvolve a ovogênese; havemos que tomar de conta que essa última se limita ao que ocorre nas células germinais (ovogonia, ovócito primário, secundário e óvulo), pelo qual depende intimamente do desenvolvimento do folículo de que essas células formam parte. Em um princípio a ativação do folículo primordial e o desenvolvimento folicular são independentes das gonadotropinas: não se conhecem os mecanismos precisos median-te os quais um folículo primordial se ativa e reinicia seu desenvolvimento, nem como se decide quais folículos, dentre as dezenas de milhares de ou centenas de milhares presentes em um ovário se reativarão em um dia em particular. A reativação trata-se de uma liberação de influência de fatores inibidores, já que os folículos primordiais se reativam espontaneamente quando cultivados in vitro, isolados do resto do tecido ovariano. Uma vez que um folículo primordial se ativa, inicia-se um longo processo de desenvolvimento que somente depois de vários meses (ao redor de cinco meses no caso dos bovinos) o levará a um estádio em que seu desenvolvimento posterior requer a presença das gonado-tropinas; daí que se diz que as primeiras etapas do desenvolvimento são independentes das gonadotropinas. Durante a fase independente de gonadotropinas, um folículo primordial que tenha sido ativado e tenha começado a crescer; passará primeiro para a etapa de folículo primá-rio, caracterizada por conter um ovócito primário que está rodeado, por sua vez, por uma capa de células da granulosa, que não são planas, e sim cúbicas. Depois, se o folículo continuar crescendo se transformará em um folículo secundário, ao qual as células da granulosa começam a proliferar (aumentando em número) e se organizam em duas ou mais capas que rodeiam o ovócito primário. Entre o ovócito e as células da granulosa que o rodeiam se forma nesta uma zona pelúcida; ainda assim o ovócito mantém contato direto com essas células, mediante o estabelecimento de pontes citoplasmáticas que atravessam a zona pelúcida. Através dessas pontes citoplasmáticas as células da granulosa podem passar nutrientes e informação ao ovócito primário. O volume e o diâmetro do ovócito primário aumentam ao mesmo tempo que as células da granulosa proliferam-se, para incrementar as capas ao redor do ovócito. De maneira gradual o citoplasma do ovócito primário aumenta até 50 vezes seu volume e a proliferação das células continua. Esses folículos que possuem cada vez mais células e portanto mais capas de células da granulosa se denominam folículos secundários. Para evitar confusões, há a necessidade de nomen-clatura ao qual o folículo vá mudando de nome de primordial a primário e logo, de secun-dário, a terciário, por sua vez, o ovócito que encontra-se em seu interior, a todo momento, segue sendo um ovócito primário. Durante a etapa dependente de gonadotropinas, os folículos secundários começam a formar um espaço cheio de líquido, o antro folicular, desse modo se convertem em folí-culos terciários. Com a utilização de outra nomenclatura, a formação do antro marca a transição entre folículos pré-antrais (sem antro) e folículos antrais (com antro). Em algum momento dessa transição entre folículo secundário e terciário, também aparece a depen-dência de folículos em direção as gonadotropinas, pelo qual somente podem seguir crescendo na presença do hormônio luteinizante (LH) e do hormônio folículo estimulante (FSH). Nos bovinos e em outras espécies (para seu estudo), os folículos antrais são dividi-dos em pequenos, médios e grandes. Embora todos eles possuam um antro folicular, dependendo do seu grau de desenvolvimento requerem diferentes concentrações de gona-dotropinas para continuar o crescimento. Os folículos antrais mais pequenos somente re-querem concentrações baixas de LH e FSH, pelo qual podem continuar crescendo em qualquer momento do ciclo estral inclusive em animais que não estão ciclando (fêmeas em anestro pré-puberal, gestacional, lactacional, estacional). Nas etapas posteriores os folículos antrais requerem primeiro concentrações elevadas de FSH, e nas etapas finais somente podem continuar crescendo na presença de pulsos frequentes de LH, pelo qual somente os folículos que encontram-se sob concentrações apropriadas desses hormônios podem seguir crescendo. Por essa razão, nos animais que se encontram em anestro de qualquer tipo somente é possível encontrar folículos antrais pequenos ou médios, segundo a espécie, e nos animais que se encontram ciclando (estro) o maior tamanho folicular encontrado em um determinado dia do ciclo dependerá das concentrações de FSH e LH presentes nesse momento e nos dias anteriores. Um folículo que chega ao estado máximo de desenvolvimento, conhecido como folículo pré-ovulatório, ao final, somente chegará a ovular se for exposto a um pico pré-ovulatório de LH. Como supracitado, cada dia na vida de uma fêmea inicia seu desenvolvimento um certo número de folículos; a grande maioria sofrem atresia, mas depois da puberdade em cada dia do ciclo estral um ou vários folículos vão encontrando ao longo do seu desenvol-vimento concentrações hormonais que lhes permite chegar na etapa de folículo pré-ovula-tório. Somente nestes folículos, e como consequência de um pico pré-ovulatório de LH, se reinicia e completa-se a primeira divisão meiótica do ovócito primário, produzindo duas células distintas. Uma delas é o ovócito secundário, que retém praticamente todo o citoplasma. Contém, assim mesmo, em seu núcleo um par de cromossomos duplos, a outra é o primeiro corpo polar, que é exclusivamente um núcleo com uma quantidade mínima de citoplasma. Na maioria das espécies ovula-se um ovócito secundário que se encontra, então, suspendido na segunda divisão meiótica. Esta segunda divisão meiótica somente reinicia-rá e completarar-se uma vez que o espermatozoide começa a penetrar sob o ovócito secundário. Ao concluir-se a divisão se forma o segundo corpo polar e completa-se a ovogênese com o qual se obtém o óvulo, célula 1n que constitui o gameta feminino. No entanto, o óvulo existe pouco tempo como tal, já que em poucos minutos/horas (depen-dendo da espécie) se produzirá a fusão do núcleo do mesmo (pró-núcleo feminino) com o do espermatozoide (pró-núcleo masculino), com o qual se completa a fertilização e se forma um novo indivíduo (o ovo ou zigoto). -/- Ondas foliculares -/- Como mencionado supra, todos os dias um determinado número de folículos pri-mordiais se ativam e começam a crescer, os quais crescem em um ritmo característico em cada espécie. Isso provoca que em qualquer momento existam nos ovários folículos pri-mordiais (que começam a crescer em alguns dias ou semanas), assim como folículos secundários em diversas etapas do desenvolvimento, os quais iniciaram seu desenvolvi-mento em semanas ou inclusive meses (segundo o grau de desenvolvimento atual). Também em qualquer momento poderá haver folículos antrais nas etapas iniciais de seu desenvolvimento (com antros que já se podem detectar em cortes histológicos mas não são visíveis macroscopicamente). Todos esses folículos chegaram até seu estado de de-senvolvimento atual (primário, secundário ou antral pequeno), independente da etapa do ciclo estral em que sejam observados ou encontrados. Nos bovinos, os folículos que chegam ao início da etapa antral iniciaram seu desenvolvimento cinco meses antes, e todavia requerem ao redor de 42 dias para chegar ao estado pré-ovulatório. Para continuar seu desenvolvimento, os folículos antrais pequenos devem encon-trar concentrações altas de FSH, que os estimulam para prosseguir o crescimento. Cada vez que se produz uma elevação nas concentrações de FSH, esse hormônio estimula o desenvolvimento de um grupo de folículos antrais pequenos, que começaram a crescer muito tempo antes e que o dia da elevação de FSH tenha alcançado o grau de desenvolvi-mento preciso para responder com eficiência a este hormônio, o qual atuará através de seus receptores nas células da granulosa para estimular a produção de estradiol, a secreção de inibina, a produção de líquido folicular e a proliferação das células da granulosa. Um grupo de folículos antrais pequenos é assim recrutado pelo FSH para acelerar seu cresci-mento e aumentar sua produção de estradiol e inibina (figura 12). Mediante um seguimento ultrassonográfico dos ovários é possível identificar pou-cos dias depois um certo número de folículos, que por haver sido recrutados começam um período de crescimento acelerado. Durante alguns dias vários folículos crescem juntos, porém depois um deles é selecionado para continuar crescendo, enquanto que o restante do grupo deixam de fazê-lo e terminam sofrendo atresia. Através da ultrassom é possível identificar o folículo selecionado, agora chamado folículo domi-nante, já que sua trajetória de crescimento sofre um desvio com respeito a seguida pelo restante do grupo. Os folículos que não foram selecionados deixam de crescer e sofrem atresia já que deixam de possuir o suporte gonadotrópico de FSH, uma vez que as concentrações desse hormônio são suprimidos pela inibina e o estradiol produzidos pelo conjunto de folículos que conformam a onda folicular (figura 12), porém o folículo mais desenvolvido do grupo se converterá em dominante. A inibina atua diretamente a nível hipofisário para reduzir a secreção de FSH. Figura 12: onda folicular e relação dos níveis de FSH, estradiol e LH. Fonte: ZARCO, 2018. -/- Figura 13: Recrutamento, seleção e dominação folicular na espécie ovina e influência do FSH e LH nas fases. Fonte: SILVA, E. I. C. da, 2019. -/- A razão pela qual o folículo dominante é capaz de continuar seu desenvolvimento apesar da baixa nas concentrações de FSH é que o folículo é o único que alcançou o grau de progresso necessário para que apareçam os receptores para LH em suas células da granulosa. Esse processo permite ao folículo dominante ser estimulado pela LH, e que requeira baixas concentrações de FSH para manter seu desenvolvimento. A secreção de LH em forma de pulsos de baixa frequência (um pulso a cada quatro a seis horas), característica da fase lútea do ciclo estral; é suficiente para permitir que um folículo dominante continue crescendo por mais dias depois da sua seleção e que mais tarde mantenha-se viável durante alguns dias embora não aumentem de tamanho. Contu-do, se durante o período viável desse folículo não seja finalizada a fase lútea e não diminuam as concentrações de progesterona, o folículo terminará sofrendo atresia devido a exigência de um padrão de secreção acelerada de LH (aproximadamente um pulso por hora) durante o desenvolvimento pré-ovulatório, que somente pode ser produzido com a ausência da progesterona. Uma vez que um folículo dominante sofre atresia deixa de produzir inibina, pelo qual as concentrações de FSH podem elevar-se novamente para iniciar o recrutamento de outro grupo de folículos a partir da qual se origina uma nova onda folicular. Durante o ciclo estral de uma vaca podem gerar-se dois ou três ondas foliculares; somente em raros casos quatro. A etapa de dominância folicular da primeira onda na grande maioria dos casos não coincide com a regressão do corpo lúteo, pelo qual o primei-ro folículo dominante quase invariavelmente termina em atresia. Em algumas vacas o fo-lículo dominante da segunda onda ainda está viável quando se produz a regressão do corpo lúteo e acelera-se a secreção de LH, pelo qual esse segundo folículo dominante se converte em folículo pré-ovulatório e, ao final ovula. Em outros animais o segundo folícu-lo dominante também perde a sua viabilidade antes da regressão do corpo lúteo, por onde nesses animais se inicia uma terceira onda folicular, da qual surge o folículo que finalmen-te ovulará depois de produzir-se a regressão do corpo lúteo. Sem importar a onda em que se origine, uma vez que um folículo dominante é ex-posto a alta frequência de secreção de LH que se produz depois da regressão do corpo lúteo, aumenta ainda mais sua secreção de estradiol até que as altas concentrações desse hormônio comecem a exercer um feedback positivo para a secreção do LH. Isso provoca-rá a aceleração da frequência de secreção do LH até que os pulsos são tão frequentes que começam a ficar por cima e produzir-se o pico pré-ovulatório de LH, que é responsável pela realização da ovulação e a maturação final do ovócito. -/- •___DIFERENÇAS ENTRE ESPERMATOGÊNESE E OVOGÊNESE -/- Enquanto que na fêmea a ovogênese inicia-se durante a vida fetal, no macho a es-permatogênese começa na puberdade. Na fêmea, a partir de um ovócito primário se origi-na um óvulo; no macho, de um espermatócito primário se produzem, teoricamente, quatro espermatozoides. Outra característica interessante é que enquanto a fêmea já conta desde o nasci-mento com todos os ovócitos que necessitará na vida adulta, o macho necessitará chegar a puberdade para iniciar o desenvolvimento das células sexuais, já que ao nascer somente possui gonócitos precursores das células germinais, células de Sertoli e intersticiais. Na vida adulta de uma fêmea, o número de células germinais desaparece paulati-namente. Uma vez iniciada a espermatogênese no macho, a cada ciclo do epitélio seminí-fero as células germinais são renovadas mantendo a provisão para toda a vida reprodutiva. Na fêmea, a meiose sofre duas interrupções em seu transcurso, e no macho é ininterrupta. Figura 14: representação em diagramação comparativa do desenvolvimento da gametogênese. -/- Principais pontos abordados sobre as diferenças entre a gametogênese masculina e feminina: ❙ Na ovogênese a meiose contêm-se em duas ocasiões esperando acontecimentos externos para prosseguir. Já na espermatogênese não existe a suspensão da meiose. ❙ A espermatogênese é um processo contínuo, enquanto que a ovogênese pode completar exclusivamente um óvulo em cada ciclo estral; já que só pode ser completada por mais de um nas espécies que ovulam vários ovócitos no caso das porcas, cadelas, gatas etc. ❙ Na espermatogênese existem células de reserva que permitem a continuação du-rante toda a vida, enquanto que na ovogênese o número de ovócitos primários é limitado. A fêmea somente conta com os que nasceu, e eles não se dividem. ❙ Na espermatogênese obtém-se até 256 espermatozoides para cada espermatogo-nia que inicia o processo, enquanto que na ovogênese somente se obtém um óvulo a partir de cada ovócito primário. ❙ Durante a espermatogênese se produz uma metamorfose que transforma as es-permátides em espermatozoides. Na ovogênese não ocorre um processo análogo. ❙ Na espermatogênese, durante a meiose produzem-se quatro espermátides a partir de cada espermatócito primário. 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Mammalian spermatogenesis and sperm structure: anatomical and compartmental analysis. In. The sperm cell: Production, maturation, fertilization, regeneration, p. 1-30, 2006. TAZUKE, Salli I. et al. A germline-specific gap junction protein required for survival of differentiating early germ cells. Development, v. 129, n. 10, p. 2529-2539, 2002. VAN STRAATEN, H. W. M.; WENSING, C. J. G. Leydig cell development in the testis of the pig. Biology of Reproduction, v. 18, n. 1, p. 86-93, 1978. TURNBULL, K. E.; BRADEN, A. W. H.; MATTNER, P. E. The pattern of follicular growth and atresia in the ovine ovary. Australian Journal of Biological Sciences, v. 30, n. 3, p. 229-242, 1977. WASSARMAN, Paul M. Gametogenesis. Londres: Academic Press, 2012. WROBEL, K.-H.; SÜß, Franz. Identification and temporospatial distribution of bovine primordial germ cells prior to gonadal sexual differentiation. Anatomy and embryology, v. 197, n. 6, p. 451-467, 1998. REFERÊNCIAS BIBLIOGRÁFICAS -/- ZARCO, L. Gametogénese. In. PORTA, L. R.; MEDRANO, J. H. H. Fisiología reproductiva de los animales domésticos. Cidade do México: FMVZ-UNAM, 2018. ZIRKIN, Barry R. et al. Endocrine and Paracrine Regulation of Mammalian Spermatogenesis. In: Hormones and Reproduction of Vertebrates. Academic Press, 2011. p. 45-57. -/- REALIZAÇÃO -/- . (shrink)

Aristotle says that ὑπαρχειν has as many senses as ‘to be true’ (PrA. , A, 36, 48b2-9) and as many ways as there are different categories. (PrA., A, 37, 49a6-9) This may mean that for every ‘is’ there is a ὑπαρχειν. Τhe reason is that Aristotle uses ὑπαρχειν in converse direction of ‘is’. The equal statement of ‘A is B’ with ὑπαρχειν is ‘B ὑπαρχει to A.’ Allen Bāck points to the difference between the use of the verb with (...) dative case and its use with a subject alone in Greek language. When it is used with the dative, it retains its basic meaning, that is, ‘be already present’ or ‘exist really.’ ‘So to say that P belongs to S is to say that P exists in S, or, if you like, that P has its being in S.’ He believes that Aristotle uses this construction to insist that primary substances alone are the fundamental being and all other things only are ‘in’ substances. Thus, when the verb is used with the dative, it expresses dependent substance relation. But when it is used with a subject alone, e.g. in ‘S ὑπάρχει,’ it expresses that the subject really exists. (OI., 17a24 and 17b2) Thus, while it is the subject which is said to be the predicate, it is the predicate which ὑπάρχει to the subject. The formula of ‘τὸ Α ὑπάρχει τῷ Β’ is equivalent to ‘τὸ Β ἐστι Α.’ He uses the word for the predication of a category on substance (e.g. Met., α, 993b24-25; Met., Z, 1029a15-16; Cat., 5, 3b24-25), the predication of secondary substance on primary substance (e.g. Met., Z, 1038b21-23; Cat., 5, 2a14-19), the predication of primary substance on nothing else but itself (e.g. Met., Z, 1040b23-24), the belonging of a verb to the subject, the belonging of axioms to a single science (Met., 1005a22-23) , the belonging of PNC to all things that are (Met., IV, 3) , in the sense of really existing (Cael. 297b22, Met., 1041b4. Cf. B503, 125-126) or merely in the sense of the predication of a predicate on a subject (e.g. OI., I, 5, 17a22-24) and especially and much more repeatedly than anywhere else in his discussion of syllogism. (e.g. PrA., A, 36, 48a40-b2; PrA., B, 22, 67b28-30; PrA., A, 24a26-28) It is also used in some related senses like mere belonging (e.g. Met., A, 989a10-14; K, 1060a9-10) or to be there. (So., B, 5, 417b23-26) Some of its derived forms are also used by Aristotle. For example, ἐνυπαρχον in the sense of the thing that is ‘in’ something; (e.g. Met., A, 991a13-16; Met., Z, 1038b29-33 and 1039a3-5) ὑπερέχον in the sense of that which contains and ὑπερεχόμενον in the sense of that which is contained in something else. (e.g. Met., Δ, 1020b26-28) In a sense, the extent of the application of ὑπαρχειν is wider than ‘is’ since it is not restricted to the nominative form in which ‘is’ is used but is applicable to other cases as well: ‘For ‘That does not belong to this’ does not always mean that ‘This is not that’ but sometimes that ‘this is not of that’ or ‘for that.’ (PsA., A, 36, 48b28-33) Allen Bāck (B503, 124) points that in the Prior Analytics Aristotle uses ‘ὑπάρχει τῷ’ and ‘κατηγορεῖσθαι κατά’ interchangeably. (e.g. at 25b37-26a4) Referring to its converse construction in respect of μετέχει (if A belongs to B, then B participates in A) as a probable reason that it may have Platonist foundations. But the question is: why does Aristotle uses this construction (B belongs to A) instead of simply saying A is B? Alexander of Aphrodisias (Apr 54.21-29) wonders why Aristotle had to adhere to such artificial language, entirely unnatural for ordinary speakers of Greek. As Jonathan Barnes points out, all the three formulas of ‘τὸ Α ὑπάρχει τῷ Β,’ ‘τὸ Α κατηγορεῖται κατὰ τοῦ Β’ and ‘τὸ Α λέγεται κατὰ τοῦ Β’ are artificial in the sense that no Greek who wanted to say that pleasure was good would normally have expressed himself by way of any of them.’ Bāck thinks Aristotle may have used it ‘to stress the primacy of primary substances as the ultimate subjects.’ He also mentions the probability that it may be to emphasize that the terms are being coupled in predication without any existence condition, a suggestion he is not himself inclined with. Robin Smith notes for Aristotle that ‘belonging to’ construction is wider than ‘predicated of’ construction because it can be used for cases that cannot easily be treated as categorical sentences. While predication is restricted to cases in which the subject term is in the nominative case, belonging can indicate, as he quotes Mignucci (480-481), ‘any possible grammatical construction for a predicative relation’ . (shrink)

Obwohl dieser Band ein wenig datiert ist, gibt es nur wenige aktuelle populäre Bücher, die sich speziell mit der Psychologie des Mordes beschäftigen und es ist ein schneller Überblick für ein paar Dollar, also noch wert die Mühe. Es macht keinen Versuch, umfassend zu sein und ist stellenweise etwas oberflächlich, wobei der Leser erwartet, die Lücken aus seinen vielen anderen Büchern und der umfangreichen Literatur über Gewalt zu füllen. Für ein Update siehe z.B. Buss, The Handbook of Evolutionary Psychology 2nd (...) ed. V1 (2016) S. 265, 266, 270–282, 388–389, 545–546, 547, 566 und Buss, Evolutionary Psychology 5th ed. (2015) P 26, 96–97,223, 293-4, 300, 309–312, 410 und Shackelford and Hansen, The Evolution of Violence (2014). Er gehört seit mehreren Jahrzehnten zu den beste Evolutions psychologen und deckt in seinen Arbeiten ein breites Spektrum an Verhaltensweisen ab, aber hier konzentriert er sich fast ausschließlich auf die psychologischen Mechanismen, die einzelne Menschen zum Mord führen, und ihre mögliche evolutionäre Funktion im EWR (Environment of Evolutionary Adaptation – d.h. die Ebenen Afrikas in den letzten Millionen Jahren oder so). -/- Buss beginnt mit der Erkenntnis, dass wie bei anderen Verhaltensweisen "alternative" Erklärungen wie Psychopathologie, Eifersucht, soziales Umfeld, Gruppendruck, Drogen und Alkohol usw. nicht wirklich erklären, da die Frage nach wie vor bleibt, warum diese mörderische Impulse erzeugen, d.h. sie sind die nahen Ursachen und nicht die ultimativen evolutionären (genetischen) Ursachen. Wie immer läuft es unweigerlich auf inklusive Fitness (genetische Fitness von Verwandten) und damit auf den Kampf um den Zugang zu Kumpels und Ressourcen hinaus, der die ultimative Erklärung für das gesamte Verhalten in allen Organismen ist. Soziologische Daten (und der gesunde Menschenverstand) machen deutlich, dass jüngere ärmere Männchen am ehesten töten. Er präsentiert seine eigenen und andere Morddaten aus Industrienationen und Stammeskulturen, konspeziertes Töten von Tieren, Archäologie, FBI-Daten und seine eigene Forschung über die Mordfantasien normaler Menschen. Viele archäologische Beweise häufen sich weiterhin von Morden, einschließlich der von ganzen Gruppen oder von Gruppen abzüglich junger Frauen, in prähistorischen Zeiten. -/- Nachdem ich Buss' Kommentare untersucht habe, präsentiere ich eine sehr kurze Zusammenfassung der absichtlichen Psychologie (die logische Struktur der Rationalität), die in meinen vielen anderen Artikeln und Büchern ausführlich behandelt wird. -/- Diejenigen, die viel Zeit haben, die eine detaillierte Geschichte mörderischer Gewalt aus evolutionärer Perspektive wollen, können Steven Pinkers "The Better Angels of Our Nature Why Violence Has Declined" (2012) und meineRezension, leicht im Netz und in zwei meiner jüngsten Bücher lesen. Kurz, Pinker stellt fest, dass Mord hat stetig und dramatisch um den Faktor etwa 30 seit unseren Tagen als Forager gesunken. Obwohl Waffen es jetzt für jeden extrem einfach machen, zu töten, ist Tötung viel seltener. Pinker glaubt, dass dies auf verschiedene soziale Mechanismen zurückzuführen ist, die unsere "besseren Engel" hervorbringen, aber ich denke, es ist hauptsächlich auf die vorübergehende Fülle von Ressourcen durch die gnadenlose Vergewaltigung unseres Planeten zurückzuführen, gepaart mit erhöhter Polizeipräsenz, mit Kommunikations- und Überwachungs- und Rechtssystemen, die es viel wahrscheinlicher machen, bestraft zu werden. Dies wird jedes Mal deutlich, wenn es sogar eine kurze und lokale Abwesenheit der Polizei gibt. -/- Wer aus der modernen zweisystems-Sichteinen umfassenden, aktuellen Rahmen für menschliches Verhalten wünscht, kann mein Buch "The Logical Structure of Philosophy, Psychology, Mindand Language in Ludwig Wittgenstein and John Searle' 2nd ed (2019) konsultieren. Diejenigen,die sich für mehr meiner Schriften interessieren, können 'Talking Monkeys--Philosophie, Psychologie, Wissenschaft, Religion und Politik auf einem verdammten Planeten --Artikel und Rezensionen 2006-2019 3rd ed (2019) und Suicidal Utopian Delusions in the 21st Century 5th ed (2019) und andere sehen. (shrink)

The dominant way to define physical entities is by appeal to ideal physics (as opposed to current physics). However, it has been worried that physicalism understood in terms of ideal physics would be too liberal to rule out “psychism”, the view that mentality exists at the fundamental metaphysical level. In this article, I argue that whereas physicalism is incompatible with some psychist cases, such as the case of “phenomenalism” in which ideal physics adopts mental concepts to denote fundamental entities, physicalism (...) should accommodate a certain type of psychist case in which fundamental mental entities are denoted by non-mental concepts in ideal physics. In so doing, I propose a distinctive account of physical entities, which asserts that physical entities are entities denoted by non-mental natural concepts in ideal physics. Physicalism thus understood is expected to be neither too liberal nor too demanding. (shrink)

Epistemic akrasia arises when one holds a belief even though one judges it to be irrational or unjustified. While there is some debate about whether epistemic akrasia is possible, this paper will assume for the sake of argument that it is in order to consider whether it can be rational. The paper will show that it can. More precisely, cases can arise in which both the belief one judges to be irrational and one’s judgment of it are epistemically rational in (...) the sense that both are supported by sufficient evidence. (shrink)

Extended Cognition (EC) hypothesizes that there are parts of the world outside the head serving as cognitive vehicles. One criticism of this controversial view is the problem of “cognitive bloat” which says that EC is too permissive and fails to provide an adequate necessary criterion for cognition. It cannot, for instance, distinguish genuine cognitive vehicles from mere supports (e.g. the Yellow Pages). In response, Andy Clark and Mark Rowlands have independently suggested that genuine cognitive vehicles are distinguished from supports in (...) that the former have been “recruited,” i.e. they are either artifacts, or, products of evolution. I argue against this proposal. There are counter examples to the claim that “Teleological” EC is either necessary or sufficient for cognition. Teleological EC conflates different types of scientific projects, and inherits content externalism’s alienation from historically impartial cognitive science. (shrink)

Methodologically rigorous description, analysis, and critique of postmodern phenomena presuppose a rigorous theory of postmodernity, for which the philosophy of Martin Heidegger holds great untapped promise. This essay explicates the basic content of Heidegger’s “metametaphysics,” since for Heidegger a “metaphysics” is the epochally prevailing projection of the meaning of being in general, and he offers a theory of Western metaphysics. I begin with Heidegger’s analysis of the “regional ontologies” of the sciences in his 1927 magnum opus Being and Time, since (...) the metametaphysical works of the “late middle” Heidegger in the 1930s–1940s extend this analytical framework to metaphysics as global ontology. I then explicate Heidegger’s views on modern metaphysics, focusing on his analyses of modern science and the philosophy of Descartes, before turning to his theory of postmodernity, which I extract from his analyses of modern technology and the philosophy of Nietzsche. (shrink)

The contents of our conscious mind can seem unpredictable, whimsical, and free from external control. When instructed to attend to a stimulus in a work setting, for example, one might find oneself thinking about household chores. Conscious content thus appears different in nature from reflex action. Under the appropriate conditions, reflexes occur predictably, reliably, and via external control. Despite these intuitions, theorists have proposed that, under certain conditions, conscious content resembles reflexes and arises reliably via external control. We introduce the (...) Reflexive Imagery Task, a paradigm in which, as a function of external control, conscious content is triggered reliably and unintentionally: When instructed to not subvocalize the name of a stimulus object, participants reliably failed to suppress the set-related imagery. This stimulus-elicited content is considered ‘high-level’ content and, in terms of stages of processing, occurs late in the processing stream. We discuss the implications of this paradigm for consciousness research. (shrink)

As a slew of recent work in epistemology has brought out, there is a range of cases where there's a strong temptation to say that prudential and (especially) moral considerations affect what we ought to believe. There are two distinct models of how this can happen. On the first, “reasons pragmatist” model, the relevant prudential and moral considerations constitute distinctively practical reasons for (or against) belief. On the second, “pragmatic encroachment” model, the relevant prudential and moral considerations affect what one (...) is epistemically justified in believing. The pragmatic encroachment model appears to have several advantages over reasons pragmatism, and this has led many recent philosophers to endorse the former. However, in this paper we argue that a version of reasons pragmatism can be (at least largely) saved from these purported disadvantages once paired with an independently plausible permissivism about epistemically justified outright belief. This hybrid view—“permissivist pragmatism”—holds that when there is more than one epistemically permitted doxastic attitude, practical (including moral) considerations can determine which epistemically permitted doxastic attitude one all-things-considered ought to have. This view avoids both the problems faced by simple versions of reasons pragmatism, and those that distinctively attend pragmatic encroachment, while preserving the advantages of each view. (shrink)

The 2015 Nepal earthquake and avalanche on Mount Everest generated one of the deadliest mountaineering disasters in modern times, bringing to media attention the physical-cultural world of high-altitude climbing. Contributing to the current sociological concern with embodiment, here we investigate the lived experience and social ‘production’ of endurance in this sociologically under-researched physical-cultural world. Via a phenomenological-sociological framework, we analyse endurance as cognitively, corporeally and interactionally lived and communicated, in the form of ‘endurance work’. Data emanate from in-depth interviews with (...) 18 high-altitude mountaineers, ten of whom experienced the 2015 avalanche. The article responds to Shilling’s (2016) call to address an important lacuna identified in sociological work: the need to investigate the embodied importance of cognition in the incorporation of culture. The concept of endurance work provides a powerful exemplar of this cognitive-corporeal nexus at work as a physical-culturally shaped, embodied practice and mode-of-thinking in the social world of high-altitude climbing. (shrink)

Respiratory rhythms sustain biological life, governing the homeostatic exchange of oxygen and carbon dioxide. Until recently, however, the influence of breathing on the brain has largely been overlooked. Yet new evidence demonstrates that the act of breathing exerts a substantive, rhythmic influence on perception, emotion, and cognition, largely through the direct modulation of neural oscillations. Here, we synthesize these findings to motivate a new predictive coding model of respiratory brain coupling, in which breathing rhythmically modulates both local and global neural (...) gain, to optimize cognitive and affective processing. Our model further explains how respiratory rhythms interact with the topology of the functional connectome, and we highlight key implications for the computational psychiatry of disordered respiratory and interoceptive inference. (shrink)

The story is written as a dialogue between a farmer and a politician. In response to the politician's indignity toward the farmer, the farmer explains his philosophy regarding ethics in contemporary society and its inevitable impossibility.

Introduction: Over the past twenty-five years the sporting body has been studied in a myriad of ways including via a range of feminist frameworks (Hall 1996; Lowe 1998; Markula 2003; George 2005; Hargreaves 2007) and gender-sensitive lenses (e.g. McKay 1994; Aoki 1996; Woodward 2008). Despite this developing corpus, studies of sport only rarely engage in depth with the ‘flesh’ of the lived sporting and exercizing body (Wainwright and Turner 2003; Allen-Collinson 2009) at least from a phenomenological angle, and in (...) relation to female embodiment. It seems that a more corporeally-grounded, phenomenological perspective on women’s sporting embodiment would be a welcome addition to extant studies. In this chapter I suggest that employing a feminist phenomenological framework can provide a powerful lens through which to explore the subjective, richly-textured, lived-body experiences of sport and exercise. Phenomenology of course offers only one of a multiplicity of avenues to investigate the body in sport, and this chapter provides just a small glimpse of its possibilities. To-date studies of sporting experience employing a phenomenological theoretical framework remain surprisingly under-developed (Kerry and Armour 2000), as do those using its ethnomethodological offspring (Coates 1999; Burke et al. 2008). Further, as Fisher (2000) notes, the significance of the interaction between phenomenology and feminism has only relatively recently begun to be explored. It seems timely, therefore, to address this intriguing, potentially productive, but sometimes uneasy nexus, focusing upon female running embodiment in this case. (shrink)

Recent years have seen a burgeoning in phenomenological research on sport, physical cultures and exercise. As editors and reviewers, however, we frequently and consistently see social science articles that claim to be ‘phenomenological’ or to use phenomenology, but the reasons for such claims are not always evident. Indeed, on closer reading, many such claims can often turn out to be highly problematic. At this point, we should clarify that our ‘terrain de sport’ constitutes what has been termed ‘empirical phenomenology’ (Martínková (...) & Parry, 2011) and more specifically from our own ‘home’ discipline, a phenomenologically inspired form of sociology. This latter tradition was developed in North America by Alfred Schütz (1972). By this, we do not mean philosophical phenomenology in all its rich and varied strands, the modern form of which was inspired by Edmund Husserl’s (1913/2002) descriptive and/or transcendental phenomenology. The term itself is derived from the Greek phainomenon, from the root phôs, meaning ‘light’, thus referring to something that is placed in the light, made apparent or shown. Phenomenology is therefore the study of phenomena, things as they present themselves to, and are perceived in consciousness. Importantly, it is not just another form of qualitative research; a point which we discuss later. (shrink)

Weather experiences are currently surprisingly under-explored and under-theorised in sociology and sport sociology, despite the importance of weather in both routine, everyday life and in recreational sporting and physical–cultural contexts. To address this lacuna, we examine here the lived experience of weather, including ‘weather work’ and ‘weather learning’, in our specific physical–cultural worlds of distance-running, triathlon and jogging in the United Kingdom. Drawing on a theoretical framework of phenomenological sociology, and the findings from five separate auto/ethnographic projects, we explore the (...) ‘weather-worlds’ and weather work involved in our physical–cultural engagement. In so doing, we address ongoing sport sociological concerns about embodiment and somatic, sensory learning and ways of knowing. We highlight how weather work provides a key example of the phenomenological conceptualisation of the mind–body–world nexus in action, with key findings delineating weather learning across the meteorological seasons that contour our British weather-related training. (shrink)

Within the sociology of sport, phenomenologically-inspired perspectives on sensory embodiment have emerged in recent years. This corpus includes investigations into the senses in water-based sports such as scuba diving (Merchant, 2011), performance swimming (Allen-Collinson et al., 2021 ; McNarry et al., 2021) and in land-based sports such as distance running (Allen-Collinson et al., 2018, 2021 ; Allen-Collinson & Jackman, 2021), and cycling (Hammer, 2015 ; Spinney, 2006). In this article, I draw upon phenomenological sociology (Allen-Collinson, 2009) (...) and ‘sensory work’, to investigate the experience of asthma in sports participants. Currently, despite the prevalence of asthma globally, there remains a lack of in-depth research on actual experiences of coping with asthma and ‘breathing battles’ in sporting contexts. Here, I draw on data from two linked research projects: a collaborative autoethnography and an interview-based study , which generated findings that highlighted sensory aspects relating to the lived experience of asthma and sporting embodiment. (shrink)

This paper argues that the plethora of experiments with decentralized social technologies (DSTs)—clusters of which are sometimes called “the Web 3.0 ecosystem” or “the Fediverse”—have brought us to a constitutional moment. These technologies enable radical innovations in social, economic, and political institutions and practices, with the potential to support transformative approaches to political economy. They demand governance innovation. The paper develops a framework of prudent vigilance for making ethical choices in this space that help to both grasp positive opportunities for (...) transformation and avoid the potentially problematic consequences. Most of our specific examples and concerns come from the blockchain/Web3 universe, as this has received the greatest investment, attention, and adoption to date. However, we aim to offer a framework for governance decision-making in conditions of uncertainty that applies more broadly to other DSTs. Specifically, under the framework of prudent vigilance, we propose a pragmatic, democratic, and pluralist approach to navigating bold experimentation with social practices and political economy enabled by these technologies. Our overarching goal is to provide a framework open to transformative improvement and constrained by guardrails and guiding values supportive of democracy, freedom, and pluralism. We take a relatively strong position, rather than simply laying out ethical issues and potential approaches. We seek to be provocative in order to spur further work and hope this paper will serve as a first bridge between academic philosophy and the DST community, which have hardly interacted to date. (shrink)

Over the past 25 years, UK government policy exhortations to promote and increase exercise and physical activity levels in the population have increased in volume. In recent years, too, there has been growing sociological interest in exercise and physical activity embodiment issues, including within phenomenologically-inspired research into lived-body experiences. This article contributes original insights to a developing body of phenomenological-sociological empirical work in this domain, in addressing the lived experience of organised exercise in outdoor environments, and specifically in theorising the (...) role of ‘lived weather’ in contouring these experiences. It thus addresses the call by Vannini et al. (2012) to remedy the notable ‘absent-presence’ of weather in much social science research. Drawing upon data from a two-year multi-disciplinary, multi-institutional ethnographic study of a nationwide exercise programme in Wales, UK, this article examines participants’ (n = 146) lived experience of weather, and theorises their ‘weather learning’, and ‘weather work’, both of which emerged as highly salient in the findings. (shrink)

Aim: The researcher studied how the teachers at Guangdong Business and Technology University manage change based on the present situation in the country. -/- Methodology: This study utilized the descriptive – comparative research design with 275 teachers as respondents. Statistical test of data includes frequency count and percentage, weighted mean, t- test and/or ANOVA. -/- Results: Teacher respondents are very much ready to manage the change for the teaching and learning based on teaching-related factors which ranked first, as well as (...) on teaching-related factors which ranked second, and on technology-related factors which ranked third. It is noticeable that technology-related factor was the least assessed factors as regards their readiness to manage the change. Generally, an over-all mean value of 3.52 reveals that teachers are very much ready to manage the change for the teaching and learning. Based on the result, teacher respondents strongly agree on their level of motivation on their teaching and learning performance. The result reveals that teachers are highly motivated in performing their job as teachers based on their own assessment. -/- Conclusion: Majority of the respondents are female teachers in middle age aiming to earn their doctoral degree and have been in the university for not more than five years. Teachers believed that they are very much ready to manage the change for the teaching and learning. They also seem to be less ready in terms of accessing professional development opportunities that focus on continuous improvement of digital-age teaching skills. The use of variety of assessment strategies applying the technology and the implementation of alternative strategies in the classroom seems to be less managed by the teachers. They also have relatively the same assessment on how ready they are to manage the change in the teaching and learning regardless of their sex, age, educational level they have attained, and the length of stay in the institution. (shrink)

That philosophy is an outlier in the humanities when it comes to the underrepresentation of women has been the occasion for much discussion about possible effects of subtle forms of prejudice, including implicit bias and stereotype threat. While these ideas have become familiar to the philosophical community, there has only recently been a surge of interest in acquiring field-specific data. This paper adds to quantitative findings bearing on hypotheses about the effects of unconscious prejudice on two important stages along career (...) pathways: tenure-track hiring and early career publishing. (shrink)

Do conceivability arguments work against physicalism if properties are causal powers? By considering three different ways of understanding causal powers and the modality associated with them, I will argue that most, if not all, physicalist powers theorists should not be concerned about the conceivability argument because its conclusion that physicalism is false does not hold in their favoured ontology. I also defend specific powers theories against some recent objections to this strategy, arguing that the conception of properties as powerful blocks (...) conceivability arguments unless a rather implausible form of emergence is true. (shrink)

: Agents are enkratic when they intend to do what they believe they should. That rationality requires you to be enkratic is uncontroversial, yet you may be enkratic in a way that does not exhibit any rationality on your part. Thus, what I call the enkratic requirement demands that you be enkratic in the right way. In particular, I will argue that it demands that you base your belief about what you should do and your intention to do it on (...) the same considerations. The idea is that, if you base your belief and your intention on different considerations, then you are inconsistent in your treatment of those considerations as reasons. The enkratic requirement demands that you be enkratic by treating considerations consistently as reasons. (shrink)

Aim: This research determined the relationship between university teachers’ professional identity and their work performance. -/- Methodology: The design that was used in this study is a Descriptive Comparative- Correlational research design using the quantitative approach. Participants in this study were taken from the 967 university teachers at Guangdong Business and Technology University from the 14 colleges. They were chosen randomly. The researcher used the Qualtrics calculator at a 5% margin of error to arrive at 275 respondents. Data analyses include (...) frequency count and percentage, weighted mean, and descriptive equivalent. A five-point scale was used in this study as a guide to answer the questionnaire. -/- Results: Based on the result, the highest manifestation of teachers’ professional identity was found to be on their professional behavior tendency which was ranked first among the four indicators. It was followed by professional values and professional belonging, while role values tend to be the least manifested professional identity based on the self -assessment of the teachers. The over-all mean value of 3.52 reveals that professional identity was highly manifested among the teachers of Guangdong Business and Technology University. Teacher respondents have manifested an outstanding work performance particularly on work attitude as this was given the highest rating by the teachers themselves. Second in rank was the interpersonal promotion, followed by completion of teaching activities which also shows an outstanding work performance. On the other hand, teachers’ work performance on student achievement was given the lowest assessment by the teachers showing a very satisfactory performance. Generally, the result reveals that teachers exhibited an outstanding work performance as perceived by themselves. Based on the result, there were no significant differences in the assessment of teacher respondents when they are grouped according to gender. This is taken to mean that male and female teachers have relatively the same assessment as regards their work performance in terms of work attitude, interpersonal promotion, completion of teaching activities, and student achievement. Generally, the result reveals that there was a significant relationship between the teachers’ professional identity and their work performance. The result reveals that professional identity of teachers has positive impact on their work performance. -/- Conclusion: Respondents are dominated by female teachers who are mostly in their middle age. A good number of teachers who have earned master’s and doctoral degrees are also evident. They perceived themselves to have a high level of professional identity specifically on professional behavior tendency, professional values, and professional belonging. Teachers have relatively the same assessments on their professional identity regardless of their gender, age, educational attainment, and monthly income. They exhibit an outstanding work performance particularly on work attitude, interpersonal promotion, and completion of teaching activities. However, they feel that they had less contribution to student achievement. Teachers have relatively the same assessments on their work performance regardless of their gender, age, educational attainment, and monthly income. Professional identity of teachers can somehow influence their work performance in general. Specifically, professional values and professional belonging give positive effect to work attitude of teachers, and to their completion of teaching activities. (shrink)

Appeals to the idea of human nature are frequent in the voluminous literature on the ethics of enhancing human beings through biotechnology. Two chief concerns about the impact of enhancements on human nature have been voiced. The first is that enhancement may alter or destroy human nature. The second is that if enhancement alters or destroys human nature, this will undercut our ability to ascertain the good because, for us, the good is determined by our nature. The first concern assumes (...) that altering or destroying human nature is in itself a bad thing. The second concern assumes that human nature provides a standard without which we cannot make coherent, defensible judgments about what is good. I will argue (1) that there is nothing wrong, per se, with altering or destroying human nature, because, on a plausible understanding of what human nature is, it contains bad as well as good characteristics and there is no reason to believe that eliminating some of the bad would so imperil the good as to make the elimination of the bad impermissible, and (2) that altering or destroying human nature need not result in the loss of our ability to make judgments about the good, because we possess a conception of the good by which we can and do evaluate human nature. I will argue that appeals to human nature tend to obscure rather than illuminate the debate over the ethics of enhancement and can be eliminated in favor of more cogent considerations. (shrink)

Carruthers argues that knowledge of our own propositional attitudes is achieved by the same mechanism used to attain knowledge of other people's minds. This seems incompatible with "privileged access"---the idea that we have more reliable beliefs about our own mental states, regardless of the mechanism. At one point Carruthers seems to suggest he may be able to maintain privileged access, because we have additional sensory information in our own case. We raise a number of worries for this suggestion, concluding that (...) Carruthers's new theory cannot clearly preserve the superior reliability of our beliefs about our own attitudes. (shrink)

Reviewed Work: The Leader's Two Bodies: Slavoj Žižek's Postmodern Political Theology by Claudia Breger.

In the United States, prohibitionist policies are used as the primary approach to combat the negative effect of substance use on society. An extensive academic literature spanning the disciplines of economics, political science, and multiculturalism documents the great social costs of the United States’ “War on Drugs” both nationally and internationally. These costs come with at best marginal effect on substance abuse and other crimes linked to the drug trade. In many cases, there is a reason to believe that these (...) policies exacerbate the problems they aim to address. This article explores psychologists’ ethical commitments to social change concerning such drug policy, given the field of psychology’s expanding commitment to social justice. We examine arguments regarding the boundaries between psychologists’ personal and professional ethics with regard to political participation. Using drug prohibition as an exemplar, we suggest that many psychologists’ political actions and professional ethics may be misaligned. Ultimately, we conclude that the endorsement of prohibitionist drug policies is in direct conflict with the guiding ethical principles put forth by the American Psychological Association’s Ethical Principles of Psychologists and Code of Conduct. (shrink)

As recently highlighted, despite a burgeoning field of sensory ethnography, the practices, production, and accountability of the senses in specific social interactional contexts remain sociologically under-explored. To contribute original insights to a literature on the sensuous body in physical–cultural contexts, here we adopt an ethnomethodologically sensitive perspective to focus on the accomplishment, social organization, and accountability of sensoriality in interaction. Exploring instances of the senses at work in social interaction, we utilize data from two ethnographic research projects to investigate the (...) production of running-together and swimming-together by skilled, experienced practitioners. We focus on two interlinked sensory modalities: auditory attunement, and vision and intercorporeality, identified as key dimensions of sensory embodiment and “togethering” in these particular domains. (shrink)

Whilst in recent years sports studies have addressed the calls ‘to bring the body back in’ to theorisations of sport and physical activity, the ‘promise of phenomenology’ remains largely under-realised with regard to sporting embodiment. Relatively few accounts are grounded in the ‘flesh’ of the lived sporting body, and phenomenology offers a powerful framework for such analysis. A wide-ranging, multi-stranded, and interpretatively contested perspective, phenomenology in general has been taken up and utilised in very different ways within different disciplinary fields. (...) The purpose of this article is to consider some selected phenomenological threads, key qualities of the phenomenological method, and the potential for existentialist phenomenology in particular to contribute fresh perspectives to the sociological study of embodiment in sport and exercise. It offers one way to convey the ‘essences’, corporeal immediacy and textured sensuosity of the lived sporting body. The use of Interpretative Phenomenological Analysis (IPA) is also critically addressed. Key words: phenomenology; existentialist phenomenology; interpretative phenomenological analysis (IPA); sporting embodiment; the lived-body; Merleau-Ponty. (shrink)

The French existentialist philosopher, Simone de Beauvoir, long ago signalled the potentially empowering force of outdoor exercise and recreation for women, drawing on feminist phenomenological perspectives. Feminist phenomenological research in sport and exercise, however, remains relatively scarce, and this article contributes to a small, developing research corpus by employing a feminist phenomenological theoretical framework to analyse lived experiences of running in ‘public’ space. As feminist theorists have argued, such space is gendered and contested, and women’s mobility remains constrained by fears (...) of harassment and violent attack. Running also generates intense pleasure, however, and embodied empowerment. Drawing on findings from two separate but linked automethodological running research projects, here I explore salient and overlapping themes cohering around lived experience of pleasure and danger in both urban and rural spaces. (shrink)

According to a traditional interpretation of Kierkegaard, he endorses a strong form of direct doxastic voluntarism on which we can, by brute force of will, make a “leap of faith” to believe propositions that we ourselves take to be improbable and absurd. Yet most leading Kierkegaard scholars now wholly reject this reading, instead interpreting Kierkegaard as holding that the will can affect what we believe only indirectly. This paper argues that Kierkegaard does in fact endorse a restricted, sophisticated, and plausible (...) version of direct doxastic voluntarism. On Kierkegaard’s view, when we take ourselves to be in an epistemically permissive situation, we have the ability to form outright beliefs (but not credences) at will in virtue of our ability to voluntarily 1) open or close inquiry and 2) determine our attitude towards epistemic risk. (shrink)

In her recent paper ‘The Epistemology of Propaganda’ Rachel McKinnon discusses what she refers to as ‘TERF propaganda’. We take issue with three points in her paper. The first is her rejection of the claim that ‘TERF’ is a misogynistic slur. The second is the examples she presents as commitments of so-called ‘TERFs’, in order to establish that radical (and gender critical) feminists rely on a flawed ideology. The third is her claim that standpoint epistemology can be used to establish (...) that such feminists are wrong to worry about a threat of male violence in relation to trans women. In Section 1 we argue that ‘TERF’ is not a merely descriptive term; that to the extent that McKinnon offers considerations in support of the claim that ‘TERF’ is not a slur, these considerations fail; and that ‘TERF’ is a slur according to several prominent accounts in the contemporary literature. In Section 2, we argue that McKinnon misrepresents the position of gender critical feminists, and in doing so fails to establish the claim that the ideology behind these positions is flawed. In Section 3 we argue that McKinnon’s criticism of Stanley fails, and one implication of this is that those she characterizes as ‘positively privileged’ cannot rely on the standpoint-relative knowledge of those she characterizes as ‘negatively privileged’. We also emphasize in this section McKinnon’s failure to understand and account for multiple axes of oppression, of which the cis/trans axis is only one. (shrink)

Kierkegaard's pseudonym Johannes Climacus famously defines faith as a risky “venture” that requires “holding fast” to “objective uncertainty.” Yet puzzlingly, he emphasizes that faith requires resolute conviction and certainty. Moreover, Climacus claims that all beliefs about contingent propositions about the external world “exclude doubt” and “nullify uncertainty,” but also that uncertainty is “continually present” in these very same beliefs. This paper argues that these apparent contradictions can be resolved by interpreting Climacus as a belief‐credence dualist. That is, Climacus holds that (...) beliefs and credences (i.e., degrees of belief) are two irreducibly distinct types of mental states. Beliefs are resolutions that close inquiry, thereby excluding doubt and reflecting subjective certainty by disregarding the possibility of error. Credences, by contrast, reflect assessments of evidential probabilities, thereby encoding a recognition of “objective uncertainty” by acknowledging the possibility of error. In addition to solving a vexing interpretive puzzle and showing how Kierkegaard anticipates contemporary views about the nature of belief and credence, this paper demonstrates that Kierkegaard developed a sophisticated account of the nature of belief, doubt, and certainty that merits serious philosophical consideration. (shrink)

On the dominant contemporary accounts of how practical considerations affect what we ought to believe, practical considerations either encroach on epistemic rationality by affecting whether a belief is epistemically justified, or constitute distinctively practical reasons for belief which can only affect what we ought to believe by conflicting with epistemic rationality. This paper argues that Søren Kierkegaard offers a promising alternative view on which practical considerations can affect what we ought to believe without either encroaching on or (necessarily) conflicting with (...) epistemic rationality by determining which among the epistemically permitted outright doxastic attitudes one should all‐things‐considered adopt. (shrink)

Discussions of the functions of biological traits generally take the notion of a trait for granted. Defining this notion is a non-trivial problem. Different approaches to function place different constraints on adequate accounts of the notion of a trait. Accounts of function based on engineering-style analyses allow trait boundaries to be a matter of human interest. Accounts of function based on natural selection have typically been taken to require trait boundaries that are objectively real. After canvassing problems raised by each (...) approach, I conclude with some facts that satisfactory notions of trait must respect. (shrink)

A key contention of Klein & Barron (2016) is that consciousness does not depend on cortical structures. A critical appraisal suggests they have overestimated the strength of their evidence.

Hannah Arendt is often--but somehow not unfailingly--credited, together with Alasdair MacIntyre, Paul Ricoeur and Charles Taylor, as being one of the central voices in the philosophical turn to the concept of narrative of a generation or more ago. Some have even cited her 1958 The Human Condition as providing a particular impetus for later accounts of narrative. This essay examines what contemporary philosophical accounts of narrative might still owe Arendt, exploring her approach to narrative in theory as well as practice. (...) The first part looks at Arendt's use of philosophical sources from the tradition--Aristotle, Augustine and Hegel--with an eye to how her appropriation of these figures differs from that of contemporary philosophers of narrative. Three of Arendt's typically bold and rich claims about narrative action emerge as important: the notion of action as revealing an agent's own daimon: the condition that such action be revealable within a world or shared public space which has resilience yet vulnerability; and the potential for agents revealed within such a world to discover some form of narrative rebirth in their efforts at storytelling. The second section examines the extent to which Arendt herself allowed those claims to be tested and thought through in her own attempts (in Men in Dark Times, Rahel Varnhagen and elsewhere) at constructing biographical narratives. (shrink)

I criticize Bourget’s intuitive and empirical arguments for thinking that all possible conscious states are underived if intentional. An underived state is one of which it is not the case that it must be realized, at least in part, by intentional states distinct from itself. The intuitive argument depends upon a thought experiment about a subject who exists for only a split second while undergoing a single conscious experience. This, however, trades on an ambiguity in "split second." Meanwhile, Bourget's empirical (...) argument is question-begging. My critique also has implications for debates about the essential temporality and unity of consciousness experience, and, phenomenal atomism. (shrink)

This article considers a novel approach to researching sporting embodiment via what has been termed ‘autophenomenography’. Whilst having some similarities with autoethnography, autophenomenography provides a distinctive research form, located within phenomenology as theoretical and methodological tradition. Its focus is upon the researcher’s own lived experience of a phenomenon or phenomena. This article examines some of the key elements of a sociological phenomenological approach to studying sporting embodiment in general before portraying how autophenomenography was utilised specifically within two recent research projects (...) on distance running. The thorny issues of epoche and bracketing within phenomenological and autophenomenographical research are addressed and some practical suggestions tentatively posited. (shrink)

According to the thesis of doxastic wronging, our beliefs can non-derivatively wrong others. A recent criticism of this view claims that proponents of the doxastic wronging thesis have no principled grounds for denying that credences can likewise non-derivatively wrong, so they must countenance pervasive conflicts between morality and epistemic rationality. This paper defends the thesis of doxastic wronging from this objection by arguing that belief bears distinctive relationships to inquiry and blame that can explain why beliefs, but not credences, can (...) non-derivatively wrong. First, forming a belief (but not updating one’s credence) closes inquiry, and suspending judgment (but not updating one’s credence) opens inquiry. Consequently, beliefs can distinctively wrong others by prematurely closing inquiry or inappropriately opening inquiry. Second, beliefs (but not credences) can constitute blame. Unfittingly blaming someone can wrong them, and hence beliefs which constitute unfitting blame can distinctively wrong. In addition to defending the claim that only beliefs can non-derivatively wrong, this paper gestures towards an ethics of belief which attends to the relationship between belief and attitudes such as inquiry, faith, trust, and blame. (shrink)

Susan Wolf’s compatibilism is unique for being ‘asymmetrical.' While holding that blameworthiness entails being able to avoid acting wrongly, she maintains that our freedom consists in single-mindedly pursuing Truth and Goodness. Comparing and contrasting her position to Saint Anselm’s seminal, libertarian approach to the same subject elicits serious questions, highlighting its drawbacks. How could freedom entail the inability to do certain things? In what sense are reasons causes? What sense can be made of a double standard for assignments of responsibility? (...) Is not self-control inconsistent with being caused to act by things independent of oneself? Does not virtue require struggling against falsehoods and evils by which one could be overcome? Wolf’s compatibilism must be rejected, I shall argue, in light of Anselm’s intuitively satisfying response to these concerns: we should prefer a philosophy that entails more of what we want from freedom without begging unanswerable questions of its own. (shrink)

This paper offers an unorthodox appraisal of empirical research bearing on the question of the low representation of women in philosophy. It contends that fashionable views in the profession concerning implicit bias and stereotype threat are weakly supported, that philosophers often fail to report the empirical work responsibly, and that the standards for evidence are set very low—so long as you take a certain viewpoint.

In “What is it like to be boring and myopic?” Kathleen Akins offers an interesting, empirically driven, argument for thinking that there is nothing that it is like to be a bat. She suggests that bats are “boring” in the sense that they are governed by behavioral scripts and simple, non-representational, control loops, and are best characterized as biological automatons. Her approach has been well received by philosophers sympathetic to empirically informed philosophy of mind. But, despite its influence, her work (...) has not met with any critical appraisal. -/- It is argued that a reconsideration of the empirical results shows that bats are not boring automatons, driven by short input-output loops, instincts, and reflexes. Grounds are provided for thinking that bats satisfy a range of philosophically and scientifically interesting elaborations of the general idea that consciousness is best understood in terms of representational functions. A more complete examination of bat sensory capabilities suggests there is something that it is like after all. -/- The discussion of bats is also used to develop an objection to strongly neurophilosophical approaches to animal consciousness. (shrink)

John Perry has recently developed a form of Compatibilism that respects the Principle of Alternatives (PA), according to which free agency requires having the ability to do more than one thing. Eschewing so-called Frankfurt counterexamples to this intuitively plausible principle, long the bête noire of those who would like to believe in free agency and Determinism, Perry argues that there is an important sense in which we can act differently than we do. It signifies the “natural” property of possessing a (...) latent ability, a notion free of the mysteriousness surrounding accounts of the freedom to do otherwise based on religious or even philosophical considerations, yet sufficient to conceptually ground our assignments of praise and blame. Perry goes on to advise his readers to abandon all such unscientific accounts in favor of his common sense approach. -/- I argue that Perry’s Compatibilism (PC) leads to the same objection as other Humean versions thereof, as well as fails to explain certain intuitions regarding self-control and initiative. I conclude with an assessment of the prospects for his proposed revision of PC, written in light of these concerns. (shrink)

Many philosophers have held that we cannot say what it is like to be a bat as they present a fundamentally alien form of life. Another view held by some philosophers, bat scientists, and even many laypersons is that echolocation is, somehow, at least in part, a kind of visual experience. Either way, bat echolocation is taken to be something very mysterious and exotic. I utilize empirical and intuitive considerations to support an alternative view making a much more mundane contention (...) about bat phenomenology: echolocatory experience probably just has an auditory character. These points also call for further reflection on our intuitions about animal consciousness and standard arguments for the explanatory gap. (shrink)