In this article, I consider the cases of religious Moorean propositions of the form ‘d, but I don't believe that d’ and ‘d, but I believe that ~d’, where d is a religious dogma, proposition, or part of a creed. I argue that such propositions can be genuinely and rationally asserted and that this fact poses a problem for traditional analysis of religious assertion as an expression of faith and of religious faith as entailing belief. In the article, I explore (...) the possibility of undermining these commonly held assumptions and argue that the assertability of religious Moorean propositions can be justified by an account of faith as an intention to form religious beliefs. In the end, I also consider the consequences of such a stance, especially concerning the debate on the ethics of religious belief and doxastic voluntarism. (shrink)

David Skrbina opens this timely and intriguing text with a suitably puzzling line from the Diamond Sutra: ‘‘Mind that abides nowhere must come forth.’’, and he urges us to ‘‘de-emphasise the quest for the specifically human embodiment of mind’’ and follow Empedocles, progressing ‘‘with good will and unclouded attention’’ into the text which he has drawn together as editor. If we do, we are assured that it will ‘‘yield great things’’ (p. xi). This, I am pleased to say, is not (...) an exercise in hyperbole. (shrink)

This essay appeared as a contribution to a special issue of European Journal of Philosophy to mark the fiftieth anniversary of the publication of P. F. Strawson’s The Bounds of Sense. In that book Strawson asks whether we should agree with Kant's claim, in his Critique of Pure Reason, that there can be only one world. What Kant means by this claim is that the four-dimensional realm that we inhabit must constitute the whole of empirical reality. Strawson gives reasons for (...) challenging this claim. This essay raises the question whether, even if Strawson is right, we may nevertheless have reason to believe that there can be only one world on a broader understanding of ‘world’. The aim is as much to clarify the issue as to settle it, although an attempt is made to motivate the view that there can indeed be only one world on this broader understanding. (shrink)

Susan Stebbing’s work on incomplete symbols and analysis was instrumental in clarifying, sharpening, and improving the project of logical constructions which was pivotal to early analytic philosophy. She dispelled use-mention confusions by restricting the term ‘incomplete symbol’ to expressions eliminable through analysis, rather than those expressions’ purported referents, and distinguished linguistic analysis from analysis of facts. In this paper I explore Stebbing’s role in analytic philosophy’s development from anti-holism, presupposing that analysis terminates in simples, to the more holist or (...) foundherentist analytic philosophy of the later 20th century. I read Stebbing as a transitional figure who made room for more holist analytic movements, e.g., applications of incomplete symbol theory to Quinean ontological commitment. Stebbing, I argue, is part of a historical narrative which starts with the holism of Bradley, an early influence on her, to which Moore and Russell’s logical analysis was a response. They countered Bradley’s holist reservations about facts with the view that the world is built up out of individually knowable simples. Stebbing, a more subtle and sympathetic reader of the British idealists, defends analysis, but with important refinements and caveats which prepared the way for a return to foundherentism and holism within analytic philosophy. (shrink)

In this paper, I look at Susan Stebbing’s articles and reviews that critically engage logical positivism. These appeared before the publication of A.J. Ayer’s Language, Truth and Logic and helped shape the early British reception of logical positivism. I highlight Stebbing’s adoption of G.E. Moore’s tripartite distinction between knowing a proposition, understanding it, and giving an analysis of it and, in light of this distinction, her focus on whether the principle of verifiability can ground a plausible account of (...) communication. Stebbing thinks not, and I reconstruct her reasons, as well as her own account of communication. In doing this, I relate her criticisms to her rejection of methodological solipsism and her dissatisfaction with the logical positivist treatment of statements about other minds and the past. I also argue that Stebbing’s work provides a bridge to later criticisms of logical positivism from ordinary language philosophers. Foregrounding Stebbing’s engagement with logical positivism, especially her focus on communication, paints a fuller picture of how the logical positivists came to be part of analytic philosophy despite having different concerns than many of the British philosophers engaging their work. (shrink)

This paper argues that justification is accessible in the sense that one has justification to believe a proposition if and only if one has higher-order justification to believe that one has justification to believe that proposition. I argue that the accessibility of justification is required for explaining what is wrong with believing Moorean conjunctions of the form, ‘p and I do not have justification to believe that p.’.

The sentences ‘p but I don’t believe p’ (omissive form) and ‘p but I believe that not-p’ (comissive form) are typical examples of Moore’s paradox. When an agent (sincerely) asserts such sentences under normal circumstances, we consider his statements absurd. The Simple Solution (Moore, Heal, Wolgast, Kriegel, et al.) finds the source of absurdity for such statements in a certain formal contradiction (some kind of like ‘p & not-p’), the presence of which is lexically disguised. This solution is (...) facing criticism since it is obvious that the denial of the contradiction allegedly hidden in Moore’s paradox will not become an expression of tautology for us. Hintikka offers another solution to Moore’s paradox. In his view, the source of absurdity is the practical inconceivability of the situation, in which the agent would be able to hold mutually incompatible (inconsistent) beliefs. The sentences ‘p but I don’t believe that p’ and ‘p but I believe that not-p’ sound absurd because they express high-ordered beliefs that no rational agent can hold. A belief expressed in the sentence ‘he believes that p’, in order to be available to the agent, must be compatible with the truth of everything the agent believes. The problem with Hintikka’s solution is that it relies on an epistemic principle that does not correspond to our general intuitions about the notion of belief. According to this principle, there must be a close connection between the sentence ‘p but I don’t believe that p’ and the sentence ‘I believe that is the case is that p but I don’t believe that p’. However, it is not difficult to imagine the context for situations when the agent asserts the sentence ‘p but I don’t believe that p’ when s/he believes that p, but in parallel does not hold any high-ordered belief about his/her belief in p. For example, the agent does not recognize oneself in a photograph after a hard plastic surgery, and when one asks him ‘who is this?’ it would not be absurd for him/her to accept the following description of his/her beliefs ‘I believe that {I am me} but I don’t believe that I believe that {I am me}’. Wittgenstein provides an alternative solution based on a descriptive analysis of the grammar of verbs we use to express, attribute, and understand each other’s psychological states. In his view, the everyday practice of using the verb ‘believe’ demonstrates a characteristic asymmetry in the semantic and logical properties of the usage of this verb in the first person. The expression ‘I believe falsely’ has no real meaning since no one can meaningfully say the sentence ‘Now I believe falsely that p’ on their own behalf. Therefore, the genuine source of absurdity is associated with situations of self-attribution of false belief by the agent. Despite its originality, Wittgenstein’s solution faces objections. For example, in a certain context, it would not be absurd to assert the sentence ‘There are no beliefs, but I don’t believe in it’, unlike the sentence ‘There are no beliefs and I believe that it is so’. The solution proposed by Wittgenstein does not allow us to correct the situation since one could assert quite reasonably and without any absurdity a sentence like ‘In fact, there are no beliefs and now I falsely believe that it is so’. Based on Evans’ principle of epistemic transparency, some researchers (Atlas, Chan, Kwon, et al.) offer another strategy for solving Moore’s paradox, in which peculiar attention is paid to the dependence of understanding and evaluating the meaning of the sentences ‘p but I do not believe that p’ and ‘p but I believe that not-p’ from the immediate context of their usage. The source of absurdity should be looked for in the established practice of the self-referential use of the pronoun ‘I’. In the researchers’ view, Moore’s paradox arises only in the context of situations where the agent asserting such sentences is conscious speaking about oneself. Therefore, there is an obvious structural analogy between the sentences of the Liar family (‘This very sentence is false’, ‘Now I am lying’, etc.) and Moore’s paradox (‘p but I don’t believe that p’, ‘p but I believe that not-p’) – self-reference is constitutive for both families of paradoxical statements. (shrink)

Susan Stebbing’s paper “Logical Positivism and Analysis” (March 1933) was unusually critical of Wittgenstein. It put up a sharp opposition between Cambridge analytic philosophy of Moore and Russell and the positivist philosophy of the Vienna Circle to which she included Wittgenstein from 1929–32. Above all, positivists were interested in analyzing language, analytic philosophers in analyzing facts. Moreover, whereas analytic philosophers were engaged in directional analysis which seeks to illuminate the multiplicity of the analyzed facts, positivists aimed at final (...) analysis which “proves” that there are simples. Stebbing’s paper urged Wittgenstein to recast his philosophy and 1933 abandon those components of it that linked him to the Vienna Circle. (shrink)

Is self-knowledge a requirement of rationality, like consistency, or means-ends coherence? Many claim so, citing the evident impropriety of asserting, and the alleged irrationality of believing, Moore-paradoxical propositions of the form < p, but I don't believe that p>. If there were nothing irrational about failing to know one's own beliefs, they claim, then there would be nothing irrational about Moore-paradoxical assertions or beliefs. This article considers a few ways the data surrounding Moore's paradox might be marshaled (...) to support rational requirements to know one's beliefs, and finds that none succeed. (shrink)

The aim of this paper is to argue that what I call the simple theory of introspection can be extended to account for our introspective knowledge of what we believe as well as what we consciously experience. In section one, I present the simple theory of introspection and motivate the extension from experience to belief. In section two, I argue that extending the simple theory provides a solution to Moore’s paradox by explaining why believing Moorean conjunctions always involves some (...) degree of irrationality. In section three, I argue that it also solves the puzzle of transparency by explaining why it’s rational to answer the question whether one believes that p by answering the question whether p. Finally, in section four, I defend the simple theory against objections by arguing that self-knowledge constitutes an ideal of rationality. (shrink)

One of Moore’s paradoxical sentence types is ‘P, but I believe ~P’. Mooreans have assumed that all tokens of that sentence type are absurd in some way: epistemically, pragmatically, semantically, or assertively. And then they proceed to debate what the absurdity really is. I argue that if one has the appropriate philosophical views, then one can rationally assert tokens of that sentence type, and one can be epistemically reasonable in the corresponding compound belief as well.

According to Jim Pryor’s dogmatism, if you have an experience as if P, you acquire immediate prima facie justification for believing P. Pryor contends that dogmatism validates Moore’s infamous proof of a material world. Against Pryor, I argue that if dogmatism is true, Moore’s proof turns out to be non-transmissive of justification according to one of the senses of non-transmissivity defined by Crispin Wright. This type of non-transmissivity doesn’t deprive dogmatism of its apparent antisceptical bite.

The ‘Ordinary Language’ philosophy of the early 20th century is widely thought to have failed. It is identified with the broader so-called ‘linguistic turn’, a common criticism of which is captured by Devitt and Sterelny (1999), who quip: “When the naturalistic philosopher points his finger at reality, the linguistic philosopher discusses the finger.” (p 280) The implication is that according to ‘linguistic’ philosophy, we are not to study reality or truth or morality etc, but the meaning of the words ‘reality’, (...) ‘truth’, ‘morality’ etc. Ordinary Language philosophy has fallen so thoroughly into disrepute because it is supposed to advocate that not only are we to study words and meanings rather than the phenomena themselves (which is apparently bad enough), but we must restrict that study to words and meanings as they occur in the language used by the ordinary speaker. A number of preposterous corollaries have been taken to follow from this view. Most seriously, perhaps, and irritatingly, is that any theory which contains ‘non-ordinary’ uses of expressions is thereby ‘meaningless’ or simply false – which is clearly absurd. In this paper I show that this is a completely inaccurate picture of Ordinary Language philosophy. My aim is to correct these persistent misinterpretations, and make possible a more sensible reassessment of the philosophy. (shrink)

During the first quarter of the twentieth century, the French philosopher Henri Bergson became an international celebrity, profoundly influencing contemporary intellectual and artistic currents. While Bergsonism was fashionable, L. Susan Stebbing, Bertrand Russell, Moritz Schlick, and Rudolf Carnap launched different critical attacks against some of Bergson’s views. This book examines this series of critical responses to Bergsonism early in the history of analytic philosophy. Analytic criticisms of Bergsonism were influenced by William James, who saw Bergson as an ‘anti-intellectualist’ ally (...) of American Pragmatism, and Max Scheler, who saw him as a prophet of Lebensphilosophie. Some of the main analytic objections to Bergson are answered in the work of Karin Costelloe-Stephen. Analytic anti-Bergsonism accompanied the earlier refutations of idealism by Russell and Moore, and later influenced the Vienna Circle’s critique of metaphysics. It eventually contributed to the formation of the view that ‘analytic’ philosophy is divided from its ‘continental’ counterpart. (shrink)

Can I be wrong about my own beliefs? More precisely: Can I falsely believe that I believe that p? I argue that the answer is negative. This runs against what many philosophers and psychologists have traditionally thought and still think. I use a rather new kind of argument, – one that is based on considerations about Moore's paradox. It shows that if one believes that one believes that p then one believes that p – even though one can believe (...) that p without believing that one believes that p. (shrink)

Nico Silins (2012, 2013, 2020) argues that conscious judgments justify self-attribution of belief in the content judged. In defending his view, he makes use of Moore’s Paradox, seeking to show how his theory can explain what seems irrational or absurd about sentences of the form, ‘p and I do not believe that p’. I show why his argument strategy is not available to defend the view that conscious judgments can justify the self-attribution of belief in the content judged. I (...) then propose an amended version of his theory, which holds that sincerely asserting a proposition—whether aloud or silently—justifies self-ascribing belief in the proposition expressed. In doing so, I draw on an argument which I made in Gregory (2018) that there is something it is like to make a sincere assertion which is different from what it is like to make an insincere assertion. The phenomenology of sincere assertion provides immediate justification for self-ascription of belief in a proposition which has been sincerely asserted; nonetheless, it may be that we need to interpret our own assertions in order to determine which propositions they express. This paves the way for showing how two competing schools of thought about self-knowledge—one which holds that self-knowledge is immediate and one which holds that self-knowledge is inferential—might be combined. (shrink)

This chapter both explains the origins of emotivism in C. K. Ogden and I. A. Richards, R. B. Braithwaite, Austin Duncan-Jones, A. J. Ayer and Charles Stevenson (along with the endorsement by Frank P. Ramsey, and the summary of C. D. Broad), and looks at MacIntyre's criticisms of emotivism as the inevitable result of Moore's attack on naturalistic ethics and his ushering in the fact/value, which was a historical product of the Enlightenment.

This brief introduction is for people who want to know the leading approaches to philosophy in the twentieth century in English-speaking countries but do not have much time to study them. The book contains texts of lectures and quizzes with explained answers. By the end of this book, you will understand what analysis is and how to practice it in a philosophical way. Moreover, you will be able to talk confidently about some of the great ideas of such philosophers as (...) L. Wittgenstein, B. Russell, G. E. Moore, A. Ayer, J. Austin, W. V. O. Quine, P. F. Strawson, and more. (shrink)

A standard strategy for defending a claim of non-identity is one which invokes Leibniz’s Law. (1) Fa (2) ~Fb (3) (∀x)(∀y)(x=y ⊃ (∀P)(Px ⊃ Py)) (4) a=b ⊃ (Fa ⊃ Fb) (5) a≠b In Kalderon’s view, this basic strategy underlies both Moore’s Open Question Argument (OQA) as well as (a variant formulation of) Frege’s puzzle (FP). In the former case, the argument runs from the fact that some natural property—call it “F-ness”—has, but goodness lacks, the (2nd order) property of (...) its being an open question whether everything that instantiates it is good to the conclusion that goodness and F-ness are distinct. And in the latter case, the argument runs from the fact that that Hesperus has, but Phosphorus lacks, the property of being believed by the ancient astronomers to be visible in the evening sky to the conclusion that Hesperus and Phosphorus are distinct. Kalderon argues that both the OQA and FP fail because in neither case is there good reason to believe that both (1) and (2) are true. The reason we are tempted to believe that they are true is because we mistake de dicto claims for de re claims. In order for FP to go through, the truth of the following de re claims needs to be established: FP1) Hesperus was believed by the ancient astronomers to be visible in the evening sky. (shrink)

Although epistemic possibility figures in several debates, those debates have had relatively little contact with one another. G. E. Moore focused squarely upon analyzing epistemic uses of the phrase, ‘It’s possible that p’, and in doing so he made two fundamental assumptions. First, he assumed that epistemic possibility statements always express the epistemic position of a community, as opposed to that of an individual speaker. Second, he assumed that all epistemic uses of ‘It’s possible that p’ are analyzable in (...) terms of knowledge, not belief. A number of later theorists, including Keith DeRose, provide alternative accounts of epistemic possibility, while retaining Moore’s two assumptions. Neither assumption has been explicitly challenged, but Jaakko Hintikka’s analysis provides a basis for doing so. Drawing upon Hintikka’s analysis, I argue that some epistemic possibility statements express only the speaker’s individual epistemic state, and that contra DeRose, they are not degenerate community statements but a class in their own right. I further argue that some linguistic contexts are belief- rather than knowledge-based, and in such contexts, what is possible for a speaker depends not upon what she knows, but upon what she believes. (shrink)

Can agents rationally inquire into things that they know? On my view, the answer is yes. Call this view the Compatibility Thesis. One challenge to this thesis is to explain why assertions like “I know that p, but I’m wondering whether p” sound odd, if not Moore-Paradoxical. In response to this challenge, I argue that we can reject one or both premises that give rise to it. First, we can deny that inquiry requires interrogative attitudes. Second, we can deny (...) the ignorance norm, on which agents are not permitted to both know and have interrogative attitudes, such as wondering. I argue that there are compelling reasons to deny the former and reasons to question the latter. Both options pave the way for further work on further inquiry. (shrink)

What does 'might' mean? One hypothesis is that 'It might be raining' is essentially an avowal of ignorance like 'For all I know, it's raining'. But it turns out these two constructions embed in different ways, in particular as parts of larger constructions like Wittgenstein's 'It might be raining and it's not' and Moore's 'It's raining and I don't know it', respectively. A variety of approaches have been developed to account for those differences. All approaches agree that both (...) class='Hi'>Moore sentences and Wittgenstein sentences are classically consistent. In this paper I argue against this consensus. I adduce a variety of new data which I argue can best be accounted for if we treat Wittgenstein sentences as being classically inconsistent. This creates a puzzle, since there is decisive reason to think that 'Might p' is classically consistent with 'Not p'. How can it also be that 'Might p and not p' and 'Not p and might p' are classically inconsistent? To make sense of this situation, I propose a new theory of epistemic modals and their interaction with embedding operators. This account makes sense of the subtle embedding behavior of epistemic modals, shedding new light on their meaning and, more broadly, the dynamics of information in natural language. -/- . (shrink)

In this essay, I develop an account of belief as commitment to the truth of a proposition. On my account, to believe p is to represent p as true by way of committing to the truth of p. To commit to the truth of p, in the sense I am interested in, is to exercise the normative power to subject one’s representation of p as true to the normative standard of truth. As I argue, my account of belief as commitment (...) of the truth explains a variety of features of belief that separate it from attitudes like acceptance, supposition, and imagination. Most importantly, it explains the distinctive connection between belief and evidence. Moreover, my account helps solve three further puzzles about belief, regarding doxastic voluntarism, the aim of belief, and Moore’s paradox. (shrink)

What is the status of the claims which make up Kant’s arguments in the Critique of Pure Reason? This question seemed to Kant’s contemporaries to require a metacritique. Strawson’s criticisms of Kant should be understood in this context: as raising a metacritical challenge about Kant’s grounds for the claims which make up his arguments. What about the claims which make up Strawson’s own arguments in The Bounds of Sense? I argue in this chapter, against what I take to be the (...) general consensus, that Strawson did not and should not have understood these claims to be analytic. Rather he is somewhat puzzlingly committed to our possessing non-analytic but still a priori knowledge of his claims. What could such knowledge consist in? I’ll extract from G.E. Moore’s early writings on Kant a model for understanding such knowledge, one which enables us to better appreciate the way in which Strawson’s methodology dovetails with Kant’s own. (shrink)

En su artículo “On Knowing One’s Own Mind” (1988), Shoemaker argumenta en favor de tres afirmaciones: (1) se requiere un autoconocimiento directo (self-acquaintance) para la cooperación racional con otras personas (porque ésta depende de que podamos decirles qué es lo que creemos e intentamos hacer); (2) el autoconocimiento directo es necesario para la deliberación sobre qué creer y qué hacer (porque no podemos ajustar racionalmente creencias y deseos sin saber qué creencias y deseos tenemos); y (3) el autoconocimiento directo es (...) una consecuencia inmediata de nuestra capacidad para reconocer el carácter paradójico de oraciones que ejemplifican la paradoja de Moore. En este capítulo trato de mostrar que las afirmaciones (1) y (2) no son correctas; la cooperación se puede llevar acabo comunicándonos exclusivamente sobre (supuestos) hechos y acciones y el ajuste racional de creencias normalmente sucede de una manera automática a un nivel de primer orden. Sin embargo, la afirmación (3) indica una relación interesante entre nuestras capacidades conceptuales y lingüísticas, por un lado, y, por el otro, nuestra capacidad de “contestar la pregunta de si creo que p poniendo en marcha el proceso (cualquiera que éste sea) mediante el cual respondo a la pregunta de si p” (Evans, 1982: 225). (shrink)

According to some critics, Aristotle’s elenctic defence (elenchos, elenchus) of the Law of Non-Contradiction (Metaphysics IV) would be ineffective because it viciously begs the question. After briefly recalling the elenctic refutation of the denier of the Law of Non-Contradiction, I will first focus on Filippo Costantini’s objection to the elenchus, which, in turn, is based on the dialetheic account of negation developed by Graham Priest. Then, I will argue that there is at least one reading of the elenchus that might (...) not be viciously question-begging. In doing so, I will leverage, reinterpret and adjust the distinction between two senses of epistemic dependence, offered by Noah Lemos and originally based on some thoughts about George Edward Moore’s ‘proof of an external world.’ The key point of my counter-objection to recover the elenchus is to use the distinction between a necessary-condition relation between propositions (p only if q) and a grounding relation between facts (the fact that an epistemic agent S believes that p is grounded in the fact that S believes that q), where p and q are the content of S’s beliefs. (shrink)

I aim to alleviate the pessimism with which some philosophers regard the 'objective attitude', thereby removing a particular obstacle which P.F. Strawson and others have placed in the way of more widespread scepticism about moral responsibility. First, I describe what I consider the objective attitude to be, and then address concerns about this raised by Susan Wolf. Next, I argue that aspects of certain attitudes commonly thought to be opposed to the objective attitude are in fact compatible with it. (...) Finally, I examine the prospects of someone who wishes to adopt the objective attitude permanently. In response to philosophers who claim that this would be psychologically impossible, I argue that our commitment to attitudes that presuppose moral responsibility can soften and fade, often without our noticing it. (shrink)

The present paper argues that there is a knowledge norm for conversational implicature: one may conversationally implicate p only if one knows p. Linguistic data about the cancellation behavior of implicatures and the ways they are challenged and criticized by speakers is presented to support the thesis. The knowledge norm for implicature is then used to present a new consideration in favor of the KK thesis. It is argued that if implicature and assertion have knowledge norms, then assertion requires not (...) only knowledge but iterated knowledge: knowing that you know that you know that... you know. Such a condition on permissible assertion is argued to be plausible only if the KK thesis is true. (shrink)

G. E. Moore famously pointed out that all sincere assertions of the form ‘p, but I don’t believe that p’ are inherently absurd. John Turri strongly disagrees with the consensus evaluation of such assertions as inherently absurd and offers a counterexample according to which it is possible to say ‘Eliminativism is true, but of course I don’t believe it’s true’ sincerely and without any absurdity. I argue in this paper that Turri’s attempt misses the point entirely, for the most (...) natural interpretations of his counterexample are either absurd or do not represent genuinely Moorean assertions. The critical analysis of Turri’s counterexample will enable me to reach the general conclusion that precludes the possibility of omissive Moorean assertions that are inherently non-absurd, at least if we hold that our assertions ought to have some normative function. (shrink)

Po-etiche che ci accompagnano. La parola, il linguaggio, l'orrore, la speranza e lo stupore: Paul Celan e Ingeborg Bachmann. La voce, il silenzio, la libertà e il linguaggio: dall'arbitrio originario a Emily Dickinson e oltre. Percorsi etici e poetici: da Spinoza a Kafka, passando per P. Ricoeur e fino a Elizabeth Bishop, Marianne Moore, Margherita Guidacci, Nadine Gordimer e Bianca Maria Frabotta .

TRANSPORTE DE GAMETAS, FERTILIZAÇÃO E SEGMENTAÇÃO -/- • _____OBJETIVO -/- O entendimento do desenvolvimento embrionário nos estágios iniciais, desde a deposição dos espermatozoides na fêmea, passando pela fertilização deste no ovócito e na formação do zigoto, é de suma importância para diferenciar especialistas em reprodução e manejo reprodutivo no mercado de trabalho e, também, durante a vida acadêmica. Compreender os processos que levam à formação do zigoto na fêmea é essencial para avaliar a capacidade reprodutiva dos animais e, mediante técnicas, (...) avaliar o trato reprodutivo da fêmea e o desenvolvimento do embrião até a formação do feto e, por fim, em um novo animal sadio na propriedade. Com esse trabalho, o estudante de veterinária ou zootecnia, que deseja se aprofundar na fisiologia da reprodução animal, identificará os mecanismos que são envolvidos no transporte dos gametas, bem como os processos que estes últimos devem completar para alcançar a fertilização e para desencadear as divisões iniciais do embrião. -/- • _____INTRODUÇÃO -/- A fertilização ou fecundação é o processo pelo qual os gametas masculino (espermatozoide) e feminino (ovócito) se fundem para gerar um novo indivíduo. Seu êxito depende da culminação adequada dos diferentes processos que devem sofrer os gametas durante sua maduração e percurso; do transporte oportuno destes no trato reprodutivo da fêmea, assim como de uma série de adaptações dos órgãos genitais internos da mãe. A segmentação refere-se às primeiras divisões celulares do embrião. -/- • _____TRANSPORTE DO OVÓCITO -/- O ovócito que é liberado na ovulação, e que se encontra coberto pelas células do cumulus (figura 1), é capturado pela fímbria do infundíbulo ao aderir aos cílios. Esse processo é altamente eficaz, inclusive em espécies onde os ovários possuem várias formações globosas, por exemplo nas porcas, onde os ovidutos capturam entre 95 e 100% dos ovócitos que são ovulados. As contrações das camadas musculares do oviduto e o movimento intenso dos cílios da mucosa faz com que as secreções fluam em direção ao útero, transportando assim o complexo cumulus-ovócito. Esse transporte é relativamente rápido até alcançar a junção da ampola com o istmo (que é considerado o local de fertilização do espermatozoide e ovócito) a partir do qual se torna lento. Devido a fêmea estar em estro, o processo está sob controle endócrino, isto é, controle hormonal através do estradiol. Nas fêmeas domésticas, ao contrário das mulheres, o transporte ao longo do oviduto é extremamente eficiente, pois os embriões passam para o útero sem dificuldade, de modo que gestações ectópicas (tubárias ou em cavidade) são quase inexistentes. A égua, frequentemente, retém por muito tempo os ovócitos não fertilizados no oviduto, provavelmente devido a não secreção de substâncias (como a prostaglandina E) que poderiam favorecer sua passagem, como se propõe que aconteça com os embriões. A figura 2 apresenta um ovócito com suas respectivas estruturas. Figura 1: ovócitos de uma vaca madurados in vitro. Nota-se as células do cumulus que os recobre. -/- Figura 2: estruturas do ovócito de uma ovelha que se encontra na etapa de ovócito secundário, depois da ovulação. Elaborado pelo autor. • _____TRANSPORTE ESPERMÁTICO -/- Para que os espermatozoides sejam capazes de fertilizar o ovócito, deverão sofrer uma série de mudanças bioquímicas e morfológicas ao longo de sua passagem pelo aparelho reprodutor tanto masculino como feminino. Uma vez produzidos na parede do túbulo seminífero, os espermatozoides são liberados em direção ao lúmen tubular e transportados passivamente para uma estrutura ramificada conhecida como rede testicular (rete testis). Dessa rede são conduzidos em direção ao epidídimo passando através de 10 a 20 ductos eferentes localizados no polo superior do testículo. O epidídimo é dividido em três seções denominadas cabeça, corpo e cauda; é constituído por um só ducto longo e tortuoso que continua com o canal deferente. Ao final desemboca nas ampolas seminais, no ducto ejaculatório e na uretra. As funções do epidídimo são as de maduração, transporte e armazenamento dos espermatozoides. O transporte através do epidídimo é lento, aproximadamente de 10 dias em touros, e segue sendo passivo. Os espermatozoides tomados da cabeça do epidídimo são ainda imaturos e incapazes de fertilizar, enquanto os armazenados na cauda são completamente maduros. Durante o trânsito pelo epidídimo os espermatozoides adquirem motilidade e o potencial para fertilizar, o acrossomo é remodelado e a gota citoplasmática migra para o flagelo e é liberada. Quando um macho ejacula com muita frequência, é possível observar espermatozoides com gota citoplasmática no sêmen, já que não há tempo suficiente para que completem sua maduração. Os espermatozoides são expulsados fora do organismo durante a cópula, na masturbação ou em emissões espontâneas. Na ejaculação, os espermatozoides que se encontram suspensos nos fluidos do testículo e do epidídimo, misturam-se ao chegar na uretra com as secreções das glândulas acessórias para formar o sêmen. Essas secreções denominadas plasma seminal, proporcionam substâncias para manter o metabolismo energético das células espermáticas, e integram suas membranas elementos que impedem uma capacitação prematura. Durante a cópula, o sêmen é depositado na vagina ou no útero, variando entre as espécies (tabela 1). Na monta natural, geralmente, o serviço ocorre no momento propício, já que está definido pela fase do ciclo estral em que a fêmea é receptiva ao macho. No entanto, na inseminação artificial, é o macho que deverá determinar o momento ideal, e para isso é importante considerar a vida média dos gametas, ao qual é muito curta no caso dos ovócitos (tabela 1). -/- Tabela 1: local de depósito do sêmen, volume da ejaculação e vida média dos gametas. Espécie Local de deposição Volume (ml) Velocidade de ejaculação Vida média do ovócito Vida média do espermatozoide Bovinos Intravaginal 2 1 – 3 seg 8 h 30 – 48 h Caninos Intravaginal 2 – 30 (10 média) 6 – 45 min 48 – 72 h 9 – 11 d Equinos Intrauterina 50 – 200 20 – 60 seg 6 – 8 h 72 – 120 h Humanos Intravaginal 3 - - 5 – 6 d Ovinos Intravaginal 1 1 – 2 seg 16 – 24 h 30 – 48 h Suínos Intrauterina 200 – 400 5 – 20 min 8 – 10 h 24 – 48 h Onde d = dias; h = horas. A vida fértil do ovócito é muito curta, portanto, o momento do serviço é de grande importância para obter altos índices de fertilização. -/- Independentemente do local em que os espermatozoides sejam depositados no aparelho reprodutor feminino, serão expostos às secreções genitais e sofrem uma série de mudanças em seu trajeto até o local de fertilização antes de penetrar no ovócito. Nas espécies em que o sêmen é depositado na parte cranial da vagina, uma parte do mesmo penetra através da cérvix, enquanto outra parte é eliminada do aparelho genital da fêmea, em pouco tempo, através do fluxo retrógrado. O meio vaginal não é adequado e imobiliza os espermatozoides em pouco tempo, pelo qual deverão entrar no útero onde o ambiente é mais propício. O transporte espermático na fêmea é o resultado da alta contratilidade, do movimento ciliar e o fluido do aparelho genital durante o estro, ao qual está sob controle endócrino e do sistema nervoso. Esse transporte é favorecido pelas características especiais do muco estral, cujas moléculas formam uma espécie de canais que facilitam a passagem dos espermatozoides. Pelo contrário, durante a fase lútea seu transporte é dificultado. Além do meio vaginal, a cérvix também atua como barreira natural para limitar a passagem dos espermatozoides, diminuindo assim a possibilidade de polispermia. Funciona, também, como um filtro que seleciona os espermatozoides aptos dos que não o são, uma vez que somente os primeiros possuem uma motilidade vigorosa que lhes permite passar pelo muco altamente hidratado. Na vaca a cérvix é considerada como um reservatório espermático. Quando atravessam a cérvix, os espermatozoides seguem sua deslocação tanto por movimento próprio como pelas contrações uterinas e tubárias. Nas espécies em que o local de depósito do sêmen do macho na fêmea é intrauterino, como equinos, a principal barreira que os espermatozoides enfrentam é a união ou junção útero-tubárica. A união entre o útero e o oviduto (istmo do oviduto) serve como reservatório funcional dos espermatozoides nas espécies domésticas. Poucos minutos depois da cópula, é possível encontrar alguns espermatozoides no oviduto, que é conhecido como fase de transporte rápido. No entanto, esses espermato-zoides não são os que participam do processo de fertilização e podem apresentar certas anormalidades. Existe um segundo tipo de transporte denominado fase sustentada, a qual consiste na migração prolongada dos espermatozoides em direção as partes mais craniais do aparelho genital feminino, que conduzem à colonização do reservatório funcional e na liberação gradual dos espermatozoides dos reservatórios espermáticos, incluindo este último. O reservatório do istmo fornece aos espermatozoides um ambiente propício, protegendo-os contra a fagocitose, prolongando assim a sua viabilidade. Aqui os esper-matozoides permanecem aderidos a superfície das células ciliadas do epitélio até a finalização de sua capacitação, depois da qual são liberados quando alteram seu padrão de motilidade flagelada, fenômeno conhecido como hipermotilidade, e migram em ondas em direção ao local da fertilização. Dos milhões de espermatozoides ejaculados, somente alguns milhares alcançarão o istmo do oviduto e um número sumamente pequeno será encontrado nas imediações do ovócito no momento da fertilização. -/- • _____CAPACITAÇÃO ESPERMÁTICA E REAÇÃO ACROSSÔMICA -/- A capacitação é um processo gradual e essencial para a fertilização. Os espermato-zoides devem passar por um dado tempo de “incubação” no aparelho genital da fêmea e sofrer uma série de mudanças antes de serem capazes de fecundar o ovócito. A capacita-ção dos espermatozoides começa quando eles entram em contato com as secreções do aparelho genital da fêmea e termina no istmo do oviduto. Durante esse percurso a superfície da cabeça do espermatozoide se modifica já que algumas moléculas como o colesterol são removidas da membrana plasmática, aumentando sua fluidez e alterando suas propriedades bioquímicas. Entre outras coisas, essa reorganização dos lipídios facilita a entrada de cálcio extracelular pelos canais iônicos e ocasiona a desestabilização da membrana, tornando-a mais fusogênica. Também são eliminados outros fatores (conhecidos genericamente como fatores descapacitantes) que expõem receptores membranais indispensáveis para a realização da união entre o espermatozoide e o ovócito durante a fertilização. Os espermatozoides capacitados apresentam um padrão de hipermotilidade e uma maior atividade metabólica, características que devem obter para que sejam capazes de penetrar as camadas do ovócito. A capacitação é necessária para que ocorra a reação acrossômica. A reação acrossomal ou acrossômica (RA) é um fenômeno de exocitose que é desencadeada pela ligação entre as proteínas e receptores localizados na membrana do espermatozoide e a zona pelúcida do ovócito (figura 3). Envolve a fusão da membrana plasmática do espermatozoide com a membrana externa de seu acrossomo; formando, assim, pequenas vesículas, cujo conteúdo de enzimas hidrolíticas, como a hialuronidase e a acrosina, é liberado em direção ao seu exterior, facilitando a penetração da zona pelúcida. A adesão do espermatozoide à zona pelúcida é específica da espécie e depende de glicoproteínas presentes na membrana dos ovócitos maduros; a cabeça do espermatozoide se une com essas glicoproteínas mediante receptores específicos e atravessam em direção oblíqua a zona pelúcida até chegar ao espaço perivitelino. Nos mamíferos, particularmente em roedores e nos humanos, algumas dessas glicoproteínas são conhecidas como ZP1, ZP2 e ZP3. Pensa-se que a união da membrana espermática a esta última é o que desencadeia a reação acrossomal. Posteriormente, as vilosidades do ovócito entram em contato com o espermatozoide e a membrana presente na secreção equatorial da cabeça do espermatozoide, que tem proteínas fusogênicas específicas, une-se a membrana plasmática do ovócito, fusionando-se e permitindo a entrada do núcleo espermático ao citoplasma (figura 4). A capacitação dos espermatozoides é fundamental para o êxito da fertilização, uma vez que apenas os aptos estarão perfeitos e íntegros para que a união e percepção das glicoproteínas presentes nos mesmos possam ocorrer de forma ideal para a penetração deste no ovócito, fertilizá-lo e formar um zigoto. Figura 3: estrutura do espermatozoide. Nota: a membrana é acrossomal e não acrossonal. Elaborado pelo autor. -/- Figura 4: eventos que ocorrem durante a fertilização. A – depois de passar através das células do cumulus, o espermatozoide entra em contato com a zona pelúcida, onde receptores da membrana plasmática reconhecem as proteínas da zona pelúcida; B – é desencadeada, então, a reação acrossomal; C – para que o espermatozoide penetre na zona pelúcida; D – ao atravessar a zona pelúcida e entrar no espaço perivitelino, a cabeça do espermatozoide entra em contato com a membrana vitelina; ambas membranas se fusionam graças ao reconhecimento de proteínas fusogênicas que estão no segmento equatorial. E – ocorre, então, que o núcleo do espermatozoide penetra no citoplasma do ovócito; uma das consequências da fusão da membrana com a cabeça do espermatozoide é a reação cortical, em que os grânulos corticais do ovócito liberam seu conteúdo em direção ao espaço perivitelino, o que resulta na alteração da estrutura da zona pelúcida e da membrana vitelina para bloquear a polispermia. Elaborado pelo autor. • _____CONSEQUÊNCIAS DA PENETRAÇÃO -/- Bloqueio da polispermia -/- A fusão das membranas dos gametas durante a penetração permite a entrada da fosfolipase C zeta (PLCζ) – fator solúvel que provém do espermatozoide – que desencadeia liberação e oscilações de Ca2+ no retículo endoplasmático. Isso, por sua vez, provoca a migração e fusão dos grânulos corticais, com a consequente liberação de enzimas, que mudam tanto a estrutura da zona pelúcida (por exemplo a inativação de ZP3), como a da membrana vitelina. Desse modo, impede-se que outros espermatozoides as penetrem, evitando assim a polispermia (figura 5). -/- Figura 5: os grânulos corticais que encontram-se na periferia do citoplasma, debaixo da superfície da membrana do ovócito, migram e fusionam-se sobre a mesma, liberando seu conteúdo no espaço perivitelino imediatamente depois da penetração do espermatozoide. A – como conse-quência, tanto a membrana vitelina como a zona pelúcida são modificadas, impedindo a entrada de mais espermatozoides, o que evita a polispermia. B – o ovócito retoma, então, sua segunda divisão meiótica, que ocasiona a expulsão do segundo corpúsculo polar, e na formação dos pronúcleos feminino e masculino. C – continuando, os pronúcleos migram, suas membranas se dissolvem e os cromossomos de ambos se condensam e se unem. Completa-se, assim, a singamia e forma-se, então, o zigoto. Elaborado pelo autor baseado nos livros de embriologia e fisiologia da reprodução conforme vida bibliografia. -/- Ativação do ovócito e formação de pronúcleos -/- Na maioria das fêmeas domésticas, com exceção da cadela, o ovócito encontra-se suspenso na metáfase II da segunda meiose no momento da ovulação. A entrada da PLCζ do espermatozoide no citoplasma do ovócito, e a consequente liberação de Ca2+, faz com que o ovócito se ative, terminando a segunda divisão meiótica e expulse o segundo corpo polar. Posteriormente, o material nuclear do ovócito se reorganiza para formar o pronú-cleo feminino. Entretanto, a membrana nuclear do espermatozoide se dissolve, a cromatina descondensa-se, as protaminas são substituídas por histonas, e se forma uma nova membrana nuclear, dando lugar ao pronúcleo masculino. -/- Singamia -/- Uma vez que os pronúcleos feminino e masculino são formados, migram para o centro do ovócito, aproximam-se, suas membranas se dispersam e os cromossomos paternos e maternos se associam, com o qual recupera a condição diploide e dá origem ao zigoto (figura 5). -/- • _____DESENVOLVIMENTO EMBRIONÁRIO -/- Poucas horas após a fertilização ocorre a primeira divisão do zigoto em duas, depois em 4, 8, 16 e 32 células, denominadas blastômeros. Essas divisões mitóticas são conhecidas como divisões de segmentação ou clivagem (figura 6), uma vez que são realizadas sem aumento do citoplasma, de modo que com cada divisão os blastômeros se tornam menores. A partir das 16 células o embrião se chama mórula, e é visto como uma massa celular compacta. A compactação deve-se a informação de proteínas de ligação entre os blastômeros. O embrião acumula líquido em seu interior, formando uma cavidade denominada blastocele. Esse processo é conhecido como blastulação; o embrião, assim, passa a ser chamado de blastocisto. Nessa etapa é possível diferenciar duas populações de células embrionárias: a massa celular interna, embrioblasto ou botão embrionário (que dará origem ao embrião), e a massa celular externa, células superficiais ou trofoblasto, do qual se originam a maioria das membranas fetais. Ao continuar a multiplicação das células e a acumulação de líquido, o blastocisto aumenta de tamanho, convertendo-se em blastocisto expandido. A zona pelúcida torna-se mais fina e, finalmente, o embrião eclode; isto é, o embrião é liberado da zona pelúcida. -/- • _____FERTILIZAÇÕES ATÍPICAS -/- Polispermia -/- É a penetração de dois ou mais espermatozoides no óvulo. Esta condição é letal nos mamíferos, já que o número cromossômico desse zigoto é maior que 2n, o envelheci-mento do ovócito da porca, como consequência do serviço tardio, favorece a apresentação da polispermia, por isso, é comum ver números de nascimentos de média de 10 a 12 leitões por parição nessa espécie. Nas aves, no entanto, a penetração de mais de um espermatozoide é normal, embora apenas um pronúcleo masculino se formará, fundindo-se com o feminino. -/- Figura 6: etapas do processo de segmentação/clivagem. Fonte: aula de reprodução da professora Domenica Palomaris, UFT. -/- Ginogênese -/- É o desenvolvimento de um embrião a partir de um óvulo normal fecundado por um espermatozoide, mas sem a fusão dos cromossomos masculinos com os da fêmea. A função do espermatozoide, nesse caso, é a de ativação do ovócito para que este inicie seu desenvolvimento, mas não há fusão com o núcleo do espermatozoide. Ocorre em plantas, em nematódeos e em algumas espécies de peixes, por exemplo a Poecilia formosa, espécie em que os ovócitos das fêmeas são ativados por machos de outra espécie relacio-nada. -/- Partenogênese -/- Consiste no desenvolvimento do embrião sem a participação do espermatozoide. Ocorre em alguns insetos, o zangão, por exemplo, é partenogenético. Também pode apresentar-se em perus, cujos embriões são machos e, geralmente, morrem antes da eclosão. -/- • _____GÊMEOS -/- Existem dois tipos de gêmeos: idênticos ou monozigóticos e os não idênticos ou dizigóticos. -/- Idênticos ou monozigóticos -/- Originam-se do mesmo zigoto, sendo assim, possuem o mesmo genótipo e um fenótipo similar e, portanto, são do mesmo sexo. Em laboratório é possível gerá-los ao seccionar uma mórula em duas ou mais partes, por meio de um micromanipulador. Uma vez que possuem o mesmo genótipo, os produtos resultantes são clones. -/- Não idênticos ou dizigóticos -/- Provêm da fertilização de dois óvulos distintos por espermatozoides diferentes. Possuem, portanto, genótipos e fenótipos diferentes, e podem ser de sexo diferente. -/- REFERÊNCIAS BIBLIOGRÁFICAS -/- ALBERTS, Bruce et al. Biologia molecular da célula. Artmed Editora, 2010. AUSTIN, Colin Russell; SHORT, Roger Valentine. Reproduction in Mammals, Book I: Germ Cells and Fertilization. 1982. BEARDEN, Henry Joe et al. Reproducción animal aplicada. México: Manual Moderno, 1982. BOSCH, P.; WRIGHT JR, R. W. The oviductal sperm reservoir in domestic mammals. Archivos de medicina veterinaria, v. 37, n. 2, p. 95-105, 2005. CAPALLEJAS, Roberto Brito; RODRÍGUEZ, Lourdes Tagle. Fisiología de la reproducción animal: con elementos de biotecnología. Editorial Félix Varela, 2010. CROXATTO, Horacio B. Physiology of gamete and embryo transport through the fallopian tube. Reproductive biomedicine online, v. 4, n. 2, p. 160-169, 2002. CUPPS, Perry T. (Ed.). Reproduction in domestic animals. Elsevier, 1991. DIEDRICH, Smidt et al. Endocrinología y Fisiología de la Reproducción de los Animales Zootécnicos. 1972. DUKES, Henry Hugh; SWENSON, Melvin J.; REECE, William O. Dukes fisiologia dos animais domésticos. Editora Guanabara Koogan, 1996. FERREIRA, A. de M. Reprodução da fêmea bovina: fisiologia aplicada e problemas mais comuns (causas e tratamentos). Juiz de Fora: Minas Gerais–Brasil, p. 422, 2010. HAFEZ, Elsayed Saad Eldin; HAFEZ, Bahaa. Reprodução animal. São Paulo: Manole, 2004. HUNTER, Ronald Henry Fraser. The Fallopian tubes in domestic mammals: how vital is their physiological activity?. Reproduction Nutrition Development, v. 45, n. 3, p. 281-290, 2005. HUNTER, R. H. F.; RODRIGUEZ‐MARTINEZ, H. Capacitation of mammalian spermatozoa in vivo, with a specific focus on events in the Fallopian tubes. Molecular Reproduction and Development: Incorporating Gamete Research, v. 67, n. 2, p. 243-250, 2004. GALINA, Carlos; VALENCIA, Javier. Reproducción de los animales domésticos. 2006. HOPPER, Richard M. (Ed.). Bovine reproduction. John Wiley & Sons, 2014. HYTTEL, Poul; SINOWATZ, Fred; VEJLSTED, Morten. Embriologia veterinária. Elsevier Brasil, 2012. KÖLLE, Sabine; REESE, Sven; KUMMER, Wolfgang. New aspects of gamete transport, fertilization, and embryonic development in the oviduct gained by means of live cell imaging. Theriogenology, v. 73, n. 6, p. 786-795, 2010. MCKINNON, Angus O. et al. (Ed.). Equine reproduction. John Wiley & Sons, 2011. OLIVERA, Martha et al. El espermatozoide, desde la eyaculación hasta la fertilización. Revista Colombiana de Ciencias Pecuarias, v. 19, n. 4, p. 426-436, 2006. PLANT, Tony M.; ZELEZNIK, Anthony J. (Ed.). Knobil and Neill's physiology of reproduction. New York: Academic Press, 2014. RODRIGUEZ-MARTINEZ, Heriberto. Role of the oviduct in sperm capacitation. Theriogenology, v. 68, p. S138-S146, 2007. SAAVEDRA LEOS, María Dolores. Estudio de la composición de los gránulos corticales y del oolema de ovocitos porcinos y bovinos madurados y fecundados in vitro. Proyecto de investigación:, 2010. SENGER, Phillip L. et al. Pathways to pregnancy and parturition. Current Conceptions, Inc, 2004. SUAREZ, Susan S. The oviductal sperm reservoir in mammals: mechanisms of formation. Biology of Reproduction, v. 58, n. 5, p. 1105-1107, 1998. VALENCIA MÉNDEZ, Javier de J. Fisiología de la reproducción porcina. 1986. -/- FIXAÇÃO DO ASSUNTO -/- 1. Defina e diferencie fertilização e segmentação. -/- 2. Disserte sobre o transporte do ovócito. Por que no istmo o transporte do ovócito se torna lento? -/- 3. Fale sobre a eficiência do transporte do gameta no trato genital da fêmea e sobre a retenção de ovócitos pela égua. -/- 4. Defina as células do cumulus e explique seu papel sobre o ovócito. -/- 5. Quais as estruturas que compõem o ovócito? Qual a função de cada uma? -/- 6. Todos os ovócitos das fêmeas domésticas são iguais? Justifique. -/- 7. Disserte sobre o papel dos hormônios e das secreções sobre o transporte do ovócito no trato genital da fêmea. -/- 8. Disserte sobre o transporte do espermatozoide. Por que há transporte rápido e lento dos espermatozoides? -/- 9. Fale sobre o local de deposição do sêmen nas espécies domésticas e como esse influen-cia na eficiência da reprodução. -/- 10. Por que a vida média do espermatozoide canino é maior que as outras espécies? -/- 11. Quais as mudanças que os espermatozoides precisam sofrer para conseguir êxito na fertilização e por quê? -/- 12. Defina fase de transporte rápido, fase sustentada e hipermotilidade. Qual a importân-cia de cada um? -/- 13. Como ocorre a reação acrossômica? -/- 14. O que é polispermia e como ocorre seu bloqueio? 15. Como ocorre a ativação do ovócito e como se formam os pronúcleos? -/- 16. O que é e qual a importância da singamia? -/- 17. Disserte sobre as divisões de segmentação e qual a importância destas para o êxito da reprodução. -/- 18. Defina e diferencia mórula e blastocisto. -/- 19. Defina e diferencie ginogênese e partenogênese. -/- 20. Qual o papel endócrino e quais hormônios e enzimas atuam sobre o transporte de gametas, sobre a fertilização e sobre a segmentação? (shrink)

Regress arguments have convinced many that reasoning cannot require beliefs about what follows from what. In this paper I argue that this is a mistake. Regress arguments rest on dubious (although deeply entrenched) assumptions about the nature of reasoning — most prominently, the assumption that believing p by reasoning is simply a matter of having a belief in p with the right causal ancestry. I propose an alternative account, according to which beliefs about what follows from what play a constitutive (...) role in reasoning. (shrink)

This article analyses in detail Wittgenstein’s ‘Cambridge period’ from his return to Cambridge in 1929 until his decease in 1951. Within the ‘Cambridge period’, scholars usually distinguish the ‘middle’ (1929–1936) and the ‘late’ (1936–1951) periods. The trigger point of Wittgenstein’s return to Cambridge and philosophy was his visit to Brouwer’s lecture on ‘Mathematics, Science, and Language’ in Vienna in March 1928. Dutch mathematician Brouwer influenced not only Wittgenstein’s ability to do philosophy again but also the development of some of his (...) ideas. Namely, for Brouwer, language was a natural development of the social history of human beings. With the help of his friends, F. P. Ramsey, J. M. Keynes, G. E. Moore, and B. Russell, in 1929 Wittgenstein returned to Cambridge. The author argues that this was the crucial turning point in his philosophy that led to the revision of some of his ideas. Wittgenstein returned from self-isolation in remote villages of Lower Austria to the intellectual academic environment, where he could discuss his ideas with intellectual interlocutors and receive their valuable remarks and comments. This article is organised in chronological order: it describes the very ‘early’ middle period of 1929–1935 involving the development of Wittgenstein’s ‘phenomenology’ and the origin of the ‘language-games’ concept in the Blue and Brown Books; 1935–1936 period of ‘romantic’ enthusiasm for Soviet Russia and a trip there; Wittgenstein’s life and work during the WWII-time; resign from teaching in Cambridge in 1947 to finally finish his Philosophical Investigations. The author suggests that the ‘romantic areal’ about the USSR was formed by Wittgenstein’s predilection for Russian poetry and literature of the nineteenth century, i.e., Tolstoy, Dostoevsky, and Pushkin. Analysing the development of Wittgenstein’s ideas on language in his Cambridge period, the author mentions the influence of N. Bakhtin and P. Sraffa. Also, the author touches upon the topic of the possibility of Marxism’s influence on Wittgenstein’s life and thought. (shrink)

This book presents Robert S. Hartman’s formal theory of value and critically examines many other twentieth century value theorists in its light, including A.J. Ayer, Kurt Baier, Brand Blanshard, Paul Edwards, Albert Einstein, William K. Frankena, R.M. Hare, Nicolai Hartmann, Martin Heidegger, G.E. Moore, P.H. Nowell-Smith, Jose Ortega y Gasset, Charles Stevenson, Paul W. Taylor, Stephen E. Toulmin, and J.O. Urmson.

Syntax has to do with rules that constrain how words can combine to make acceptable sentences. Semantics (Frege and Russell) concerns the meaning of words and sentences, and pragmatics (Austin and Grice) has to do with the context bound use of meaning. We can hence distinguish between three competing principles of translation: S—translation preserves the syntax of an original text (ST) in the translation (TT); M—translation preserves the meaning of an ST in a TT; and P—translation preserves the pragmatics of (...) an ST in a TT. A prominent form of P is functionalism defended by linguists and translation theorists (J.R. Firth, Eugene Nida, Susan Bassnett and many others) and historically was defended by philosophers (Russell, Ogden and Richard) but abandoned by philosophers and criticized by Wittgenstein. If we adopt M, then a TT will always say exactly what the ST says, and hence all subsequent TTs, even alternative ones produced via M, will be consistent with each other. But if we adopt P, in contrast, we have no reason to believe that the TTs will say what the ST does, and moreover they can contradict each other. If such contradictory translations are produced on the basis of the totality of empirical evidence, it results in what Quine called the indeterminacy of translation. Yet, P is not easy to reject. In many cases, translation in accordance with M where the meaning to be preserved is linguistic results in TTs that are failures. In contrast to a language focused approach to semantics, I close by following a lead in the translation theory literature of identifying text-types (genres) as a tool for identifying translatable content in an ST. To individuate text-types I identify them with disciplines, as elucidated by the 2nd century Patañjali’s Yoga Sūtra. This allows for the definition of textual meaning as the discipline relative pragmatics of an ST and further for translation to proceed by way of M, while taking the intuitions that motivate P seriously. Translations that preserve textual meaning will not only have the same meaning as each other but will be pragmatically felicitous. (shrink)

This paper critically examines currently influential transparency accounts of our knowledge of our own beliefs that say that self-ascriptions of belief typically are arrived at by “looking outward” onto the world. For example, one version of the transparency account says that one self-ascribes beliefs via an inference from a premise to the conclusion that one believes that premise. This rule of inference reliably yields accurate self-ascriptions because you cannot infer a conclusion from a premise without believing the premise, and so (...) you cannot infer from a premise that you believe the premise unless you do believe it. I argue that this procedure cannot be a source of justification, however, because one can be justified in inferring from p that q only if p amounts to strong evidence that q is true. This is incompatible with the transparency account because p often is not very strong evidence that you believe that p. For example, unless you are a weather expert, the fact that it will rain is not very strong evidence that you believe it will rain. After showing how this intuitive problem can be made precise, I conclude with a broader lesson about the nature of inferential justification: that beliefs, when justified, must be underwritten by beliefs, when justified, must be underwritten by evidential relationships between the facts or propositions which those beliefs represent. (shrink)

That knowledge is factive, that is, that knowledge that p requires that p, has for a long time typically been treated as a truism. Recently, however, some authors have raised doubts about and arguments against this claim. In a recent paper in this journal, Michael Shaffer presents new arguments against the denial of the factivity of knowledge. This article discusses one of Shaffer’s objections: the one from “inconsistency and explosion”. I discuss two potential replies to Shaffer’s problem: dialetheism plus paraconsistency (...) and epistemic pluralism. This is not to be understood so much as a criticism of Shaffer’s view but rather as a request to develop his very promising objection from inconsistency and explosion further. (shrink)

Knowledge is not only true belief, because some true beliefs are supported by lucky guesswork and hence do not describe knowledge. Knowledge requires possession of good reasons that elevates a true belief to the status of knowledge. This is justification condition. However, this concept of knowledge has been disputed by Gettier and requires modification. Some philosophers say that we must add the condition that the complete justification that a man has for what he believes must not depend on any false (...) sentence. In this paper, I will examines two theories of justification in detail, and 9 refer briefly to two theories. A simple concept of epistemic justification is that a person is justified in believing that (p), if his belief that (p) is based on adequate grounds. The first theory is the foundations theory, or foundationalism, according to it, knowledge and justification are based on some sort of foundation. Such foundation consists of basic beliefs that are justified in themselves, upon which the justification for all other beliefs rests. The second theory is the coherence theory, or coherentism. This theory is based on the thesis that belief is justified if it belongs to a coherent set of beliefs. Coherentists deny the need for basic beliefs because all beliefs may be justified by their relation to others by mutual support. The third theory is the externalist theory. The externalist says that we need neither basic beliefs nor coherence to acquire knowledge, but rather right kind of external relationship to get knowledge. According to Goldman the appropriate relationship is causal. Armstrong and Dretske have argued that the relationship results from some law of nature. The fourth theory is foundherentism. This theory is presented by Susan Haack as an alternative to foundationalism and coherentism. It agrees with coherentism that there are no basic beliefs and agrees with foundationalism that experience can be relevant to empirical justification. ليست المعرفة اعتقاداً صادقاً فحسب، لأن بعض الاعتقادات الصادقة يتم تأييدها عن طريق التخمين، ولذلك لا توصف بأنها معرفة. فالمعرفة تتطلب امتلاك الأسباب الجيدة التي ترفع الاعتقاد الصادق إلى مرتبة المعرفة، وهذا هو شرط التسويغ. ومع ذلك فقد جادل جيتير في هذا التصور للمعرفة وطالب بتعديله. وقال بعض الفلاسفة لابد من أن نضيف شرطا مؤداه أن التسويغ الكامل الذي يملكه الإنسان لما يعتقده يجب ألا يعتمد على أية جملة كاذبة. وفي هذا البحث سوف أفحص نظريتين في التسويغ بشيء من التفصيل، وأشير بإيجاز إلى نظريتين. والتصور البسيط للتسويغ المعرفي هو أن الشخص يكون مسوغا في الاعتقاد بأن (ق) إذا كان اعتقاده بأن (ق) قائم على أسس كافية. والنظرية الأولى هي نظرية الأسس أو نزعة الأسس، وتبعا لهذه النظرية فإن المعرفة والتسويغ يقومان على نوع ما من الأساس. ويتألف هذا الأساس من اعتقادات أساسية تكون مسوغة في ذاتها، ويرتكز عليها تسويغ جميع الاعتقادات الأخرى. والنظرية الثانية هي نظرية الاتساق أو نزعة الاتساق. وتقوم هذه النظرية على الدعوى القائلة إن الاعتقاد يكون مسوغا إذا كان ينتمي إلى مجموعة متسقة من الاعتقادات. وينكر أصحاب نظرية الاتساق الحاجة إلى اعتقادات أساسية لأن جميع الاعتقادات يجوز تسويغها عن طريق علاقتها باعتقادات أخرى بواسطة التأييد المتبادل. أما النظرية الثالثة فهي النظرية الخارجية. ويقول صاحب النظرية الخارجية إننا لا نحتاج إلى اعتقادات أساسية ولا إلى اتساق لكي نحصل على المعرفة، وإنما نحتاج بالأحرى إلى النوع الصحيح من العلاقة الخارجية بين الاعتقادات والواقع للحصول على المعرفة. وتبعا لجولدمان فإن العلاقة الملائمة هي علاقة سببية. أما ارمسترونج ودرتسكي فقد حاولا البرهنة على أن العلاقة تنشأ من قانون ما في الطبيعة. والنظرية الرابعة هي نزعة بين الأسس والاتساق. وتقدم سوزان هاك هذه النظرية بديلاً لنزعة الأسس ونزعة الاتساق. وتتفق نظريتها مع نزعة الاتساق على أنه لا توجد اعتقادات أساسية، وتتفق مع نزعة الأسس على أن التجربة يمكن أن تكون ملائمة للتسويغ التجريبي. (shrink)

In trying to answer the question What is analytic philosophy? I shall follow two methodological principles. (i) The first was suggested by Peter Hacker and reads: ‘Any characterisation of “analytic philosophy” which excludes Moore, Russell and the later Wittgenstein, as well as the leading figures of post War analytic philosophy [for us these are John Wisdom, Ryle, Austin, Strawson and Dummett], must surely be rejected.’ (Hacker 1996a, p. 247) The correct definition of analytic philosophy must cohere with the philosophy (...) of its generally recognized founding fathers. (ii) Any characterisation of ‘analytic philosophy’ which was massively represented in the history of philosophy in the past, must be rejected too. To be sure, Moore, Russell and Wittgenstein, and later also Ryle, Austin and their friends, were doing a type of philosophy which they consciously understood as new—it was intrinsically New Philosophy. The problem was only that this newness was difficult to identify and define. (shrink)

This is the text of Dr. Sterrett's replies to an interviewer's questions for simplycharly.com, a website with interviews by academics on various authors, philosophers, and scientists.

After the 2016 election of Donald Trump, many commentators latched on to the accusations Rorty levels at the American Left in Achieving Our Country. Rorty foresaw, they claimed, that the Left's preoccupation with cultural politics and neglect of class politics would lead to the election of a "strongman" who would take advantage of and exploit a rise in populist sentiment. -/- In this paper, I generally agree with these readings of Rorty; he does think that the American Left has made (...) the mistake of putting class on the political backburner. However, I suggest that this position follows from his view that economic security is vital for solidarity. Because economic security is under increasing threat in contemporary America, so too is solidarity. If greater solidarity is a goal of liberal democracy, then class politics, aimed at ending selfishness, ought to be as much a priority for the American Left as is cultural politics, aimed at ending sadism. (shrink)

This essay constitutes an attempt to probe the very idea of a saying/showing distinction of the kind that Wittgenstein advances in the Tractatus—to say what such a distinction consists in, to say what philosophical work it has to do, and to say how we might be justified in drawing such a distinction. Towards the end of the essay the discussion is related to Wittgenstein’s later work. It is argued that we can profitably see this work in such a way that (...) a saying/showing distinction arises there too. In particular, in the final sub-section of the essay, it is suggested that we can see in Wittgenstein’s later work an inducement to say what we are shown. (shrink)

There are kinds of dialogue that support social justice and others that do the reverse. The kinds of dialogue that supports social justice requires that anger be bracketed and that hiding in safe spaces be eschewed. All illegitimate ad hominem/ad feminem attacks are ruled out from the get-go. No dialogical contribution can be down-graded on account of the communicator’s gender, race, or religion. As well, this social justice communicative approach unapologetically privileges reason in full view of theories and strategies that (...) might seek to undermine reasoning as just another illegitimate form of power. -/- On the more positive side, we will argue that social justice dialogue will enhanced by a kind of “communicative upgrading” that amplifies “person perception,” foregrounds the impersonal forces within our common social spaces rather than the “baddies” within, and orients the dialogical trajectory toward the future rather than the past. Finally, we will argue that educators have a pressing responsibility to guide their students through social justice dialogue so that their contributions contribute to the amelioration of injustice, rather than rendering the terrain more treacherous. (shrink)

Summary Analogue models are actual physical setups used to model something else. They are especially useful when what we wish to investigate is difficult to observe or experiment upon due to size or distance in space or time: for example, if the thing we wish to investigate is too large, too far away, takes place on a time scale that is too long, does not yet exist or has ceased to exist. The range and variety of analogue models is too (...) extensive to attempt a survey. In this article, I describe and discuss several different analogue model experiments, the results of those model experiments, and the basis for constructing them and interpreting their results. Examples of analogue models for surface waves in lakes, for earthquakes and volcanoes in geophysics, and for black holes in general relativity, are described, with a focus on examining the bases for claims that these analogues are appropriate analogues of what they are used to investigate. A table showing three different kinds of bases for reasoning using analogue models is provided. Finally, it is shown how the examples in this article counter three common misconceptions about the use of analogue models in physics. (shrink)

Dedication: I would like to dedicate this essay to Mort Morehouse, whose intelligence, warmth, and good humour sustains NAACI to this day. I would like, too, to dedicate this essay to Nadia Kennedy who, in her paper “Respecting the Complexity of CI,” suggests that respect for the rich non-reductive emergent memories and understandings that evolve out of participating in the sort of complex communicative interactions that we experienced at the 2012 NAACI conference requires “a turning around and looking back so (...) that we might understand it better.” Thus, though “we cannot grasp the essence of the system in some determinate way, since each description provides a limited view, and portrays some aspect of the system from a specific position inside or outside it, and at a specific point in time,” nonetheless respect requires that we try “to take different ‘snapshots’ of such systems and attempt to make sense of them.” It is as a result of this urging that the following snapshot was attempted. My thanks to Nadia for being such an inspiration, and to all the participants for making this conference such a memorable occasion. (shrink)

Marshalling a mind-numbing array of data, Harvard political scientist Robert D. Putnam, in his book Bowling Alone, shows that on virtually every conceivable measure, civic participation, or what he refers to as “social capital,” is plummeting to levels not seen for almost 100 years. And we should care, Putnam argues, because connectivity is directly related to both individual and social wellbeing on a wide variety of measures. On the other hand, social capital of the “bonding kind” brings with it the (...) ugly side effect of animosity toward outsiders. Given the increasing heterogeneity of our world, the goal therefore must be to enhance connectivity of the “bridging sort,” i.e., connecting across differences. This, in turn, requires that we first clarify what bridging communicative styles looks like. Examining communication as it might transpire in Kant’s kingdom of ends, through the perspective of Habermas’ “communicative action,” and within the scientific community, offers a compelling suggestion that there is a way of communicating such that, if adopted, one would come to view others as if they were persons, i.e., that a bridging communicative style facilitates a kind of bonding that sees through differences toward the commonality of personhood. This paper will briefly explore how communicating toward personhood might be promoted. (shrink)

Philosophy has a dirty little secret and it is this: a whole lot of philosophers have swallowed the mechanistic billiard ball deterministic view of human action—presumably because philosophy assumes that science demands it, and/or because modern attempts to articulate in what free will consists seem incoherent. This below-the-surface-purely-academic commitment to mechanistic determinism is a dirty little secret because an honest public commitment would render virtually all that is taught in philosophy departments incomprehensible. Can “lovers of wisdom” really continue to tolerate (...) such a heavy burden of hypocrisy? For it is maximally hypocritical, is it not, to teach ethics, or existentialism, or political philosophy, or critical thinking, or indeed to teach anything at all if one views the bodies of humans as entities determined by forces that are describable entirely under the auspices of physical/chemical laws. The only option, it would seem, to avoid such hypocrisy is to go out of business. After all, either base metal can be turned into gold, or it cannot. We found out long ago that it cannot, and so alchemy was rightly banished into the dustbin of history. Likewise, either philosophy can enhance the wisdom quotient of its disciples as its name implies, and thus override billiard ball mechanics, or it cannot. And if it cannot, it deserves to follow alchemy to an ignominious end. (shrink)

This thesis focuses on expressively rich languages that can formalise talk about probability. These languages have sentences that say something about probabilities of probabilities, but also sentences that say something about the probability of themselves. For example: (π): “The probability of the sentence labelled π is not greater than 1/2.” Such sentences lead to philosophical and technical challenges; but can be useful. For example they bear a close connection to situations where ones confidence in something can affect whether it is (...) the case or not. The motivating interpretation of probability as an agent's degrees of belief will be focused on throughout the thesis. -/- This thesis aims to answer two questions relevant to such frameworks, which correspond to the two parts of the thesis: “How can one develop a formal semantics for this framework?” and “What rational constraints are there on an agent once such expressive frameworks are considered?”. (shrink)

Orang-utans played a communication game in two studies testing their ability to produce and comprehend requestive pointing. While the ‘communicator’ could see but not obtain hidden food, the ‘donor’ could release the food to the communicator, but could not see its location for herself. They could coordinate successfully if the communicator pointed to the food, and if the donor comprehended his communicative goal and responded pro-socially. In Study 1, one orang-utan pointed regularly and accurately for peers. However, they responded only (...) rarely. In Study 2, a human experimenter played the communicator’s role in three conditions, testing the apes’ comprehension of points of different heights and different degrees of ostension. There was no effect of condition. However, across conditions one donor performed well individually, and as a group orang-utans’ comprehension performance tended towards significance. We explain this on the grounds that comprehension required inferences that they found difficult – but not impossible. The finding has valuable implications for our thinking about the development of pointing in phylogeny. (shrink)

The aim of this essay is to characterize the issue whether tense is real. Roughly, this is the issue whether, given any tensed representation, its tense corresponds in some suitably direct way to some feature of reality. The task is to make this less rough. Eight characterizations of the issue are considered and rejected, before one is endorsed. On this characterization, the unreality of tense is equivalent to the unity of temporal reality. The issue whether tense is real, so characterized, (...) is then related to Kant’s deduction of the categories in his Critique of Pure Reason. It is argued that Kant’s deduction does not provide the argument for the unreality of tense that it may appear to. The conclusion drawn at the end of the essay is that the unreality of tense cannot be argued for—not because tense is real, but because, even if it is unreal, its unreality is basic. (shrink)