Nicholas Rescher’s way of understanding process philosophy reflects the ambitions of his own philosophical project and commits him to a conceptually ideal interpretation of process. Process becomes a transcendental idea of reflection that can always be predicated of our knowledge of the world and of the world qua known, but not necessarily of reality an sich. Rescher’s own taxonomy of process thinking implies that it has other variants. While Rescher’s approach to process philosophy makes it intelligible and appealing to (...) mainstream analytic philosophy, it leaves behind the more daring ideas of Bergson, James, and Whitehead, all of whom envisioned the primordial reality of process in a radical ontology of becoming. This variant of process thought can be construed as coherent and self-consistent, but not without relinquishing the correspondence theory of truth and embracing challenging ideas that bring us in close proximity to existentialism, apophatic theology, and Buddhism. (shrink)

"Understanding Scientific Progress constitutes a potentially enormous and revolutionary advancement in philosophy of science. It deserves to be read and studied by everyone with any interest in or connection with physics or the theory of science. Maxwell cites the work of Hume, Kant, J.S. Mill, Ludwig Bolzmann, Pierre Duhem, Einstein, Henri Poincaré, C.S. Peirce, Whitehead, Russell, Carnap, A.J. Ayer, Karl Popper, Thomas Kuhn, Imre Lakatos, Paul Feyerabend, Nelson Goodman, Bas van Fraassen, and numerous others. He lauds Popper for advancing (...) beyond verificationism and Hume’s problem of induction, but faults both Kuhn and Popper for being unable to show that and how their work could lead nearer to the truth." —Dr. LLOYD EBY teaches philosophy at The George Washington University and The Catholic University of America, in Washington, DC "Maxwell's aim-oriented empiricism is in my opinion a very significant contribution to the philosophy of science. I hope that it will be widely discussed and debated." – ALAN SOKAL, Professor of Physics, New York University "Maxwell takes up the philosophical challenge of how natural science makes progress and provides a superb treatment of the problem in terms of the contrast between traditional conceptions and his own scientifically-informed theory—aim-oriented empiricism. This clear and rigorously-argued work deserves the attention of scientists and philosophers alike, especially those who believe that it is the accumulation of knowledge and technology that answers the question."—LEEMON McHENRY, California State University, Northridge "Maxwell has distilled the finest essence of the scientific enterprise. Science is about making the world a better place. Sometimes science loses its way. The future depends on scientists doing the right things for the right reasons. Maxwell's Aim-Oriented Empiricism is a map to put science back on the right track."—TIMOTHY McGETTIGAN, Professor of Sociology, Colorado State University - Pueblo "Maxwell has a great deal to offer with these important ideas, and deserves to be much more widely recognised than he is. Readers with a background in philosophy of science will appreciate the rigour and thoroughness of his argument, while more general readers will find his aim-oriented rationality a promising way forward in terms of a future sustainable and wise social order."—David Lorimer, Paradigm Explorer, 2017/2 "This is a book about the very core problems of the philosophy of science. The idea of replacing Standard Empiricism with Aim-Oriented Empiricism is understood by Maxwell as the key to the solution of these central problems. Maxwell handles his main tool masterfully, producing a fascinating and important reading to his colleagues in the field. However, Nicholas Maxwell is much more than just a philosopher of science. In the closing part of the book he lets the reader know about his deep concern and possible solutions of the biggest problems humanity is facing."—Professor PEETER MŰŰREPP, Tallinn University of Technology, Estonia “For many years, Maxwell has been arguing that fundamental philosophical problems about scientific progress, especially the problem of induction, cannot be solved granted standard empiricism (SE), a doctrine which, he thinks, most scientists and philosophers of science take for granted. A key tenet of SE is that no permanent thesis about the world can be accepted as a part of scientific knowledge independent of evidence. For a number of reasons, Maxwell argues, we need to adopt a rather different conception of science which he calls aim-oriented empiricism (AOE). This holds that we need to construe physics as accepting, as a part of theoretical scientific knowledge, a hierarchy of metaphysical theses about the comprehensibility and knowability of the universe, which become increasingly insubstantial as we go up the hierarchy. In his book “Understanding Scientific Progress: Aim-Oriented Empiricism”, Maxwell gives a concise and excellent illustration of this view and the arguments supporting it… Maxwell’s book is a potentially important contribution to our understanding of scientific progress and philosophy of science more generally. Maybe it is the time for scientists and philosophers to acknowledge that science has to make metaphysical assumptions concerning the knowability and comprehensibility of the universe. Fundamental philosophical problems about scientific progress, which cannot be solved granted SE, may be solved granted AOE.” Professor SHAN GAO, Shanxi University, China . (shrink)

This paper considers objections to Popper's views on scientific method. It is argued that criticism of Popper's views, developed by Kuhn, Feyerabend, and Lakatos, are not too damaging, although they do require that Popper's views be modified somewhat. It is argued that a much more serious criticism is that Popper has failed to provide us with any reason for holding that the methodological rules he advocates give us a better hope of realizing the aims of science than any other set (...) of rules. Consequently, Popper cannot adequately explain why we should value scientific theories more than other sorts of theories ; which in turn means that Popper fails to solve adequately his fundamental problem, namely the problem of demarcation. It is suggested that in order to get around this difficulty we need to take the search for explanations as a fundamental aim of science. (shrink)

Book review of Anderson-Gold & Muchnik (eds), Kant's Anatomy of Evil.

Imre Lakatos and Paul Feyerabend initially both accepted Popper's philosophy of science, but then reacted against it, and developed it in different directions. Lakatos sought to reconcile Kuhn and Popper by characterizing science as a process of competing research programmes, competing fragments of Kuhn's normal science. Feyerabend emphasized the need to develop rival theories to facilitate severe empirical testing of accepted theories, but then, as a result of a disastrous mistake, came to hold that theories that are incompatible with (...) one another cannot be compared empirically. He ended up rejecting method in science. All four philosophers, Popper, Kuhn, Lakatos and Feyerabend missed the decisive defect in Popper's philosophy of science: persistent acceptance of unified theories only when endlessly many empirically more successful disunified rivals are available means that physics makes a big, highly problematic metaphysical assumption about the nature of the universe: it is such that some kind of underlying unity exists in nature. We need to adopt a new conception of science. In order to subject this implicit metaphysical conjecture to sustained critical assessment in an attempt to improve it, we need to see science as making a hierarchy of metaphysical assumptions about the knowability and comprehensibility of the universe, these assumptions becoming less substantial and more likely to be true as we ascend the hierarchy. Elements of Popper, Kuhn and Lakatos are to be found in this picture, but it also differs radically from all three. It more closely resembles Einstein's mature views about the nature of science. (shrink)

After stating "I am gay" Navy Lieutenant Paul G. Thomasson was honorably discharged from the military. In Thomasson v. Perry (1996), the United States Court of Appeals for the Fourth District affirmed Thomasson's discharge. Thomasson is now considered the leading case evaluating the U.S. military's "don't ask, don't tell" policy. In this paper, I show that the court's analysis of the Department of Defense policy rests of two unarticulated and undefended assumptions about sexuality. The first is that an act (...) of sex is essentially defined in terms of the sexual orientation of the persons engaging in that act. The second is that whether or not a person is an open homosexual determines the essential nature of the homosexual acts of others. I conclude that both assumptions are untenable, therefore the "don't ask, don't tell" policy is indefensible. (shrink)

The practical problem of how to conduct oneself as a Christian and a Philosopher or Bioethicist in public debate an when asked to be engaged in government committees is difficult. One solution that has had some support has been to approach the issues on the grounds of our natural law tradition but understood anthropocentrically – the ultimate end is not communion with God by integral human development. This is often called New Natural Law (NNL). This separation of Philosophy and Theology (...) has had its critics and most notably the current Poe and his immediate predecessor. In their own writing addressed to people of goodwill, they took a different approach that was essentially Christocentric and involving s close partnership between Philosohy and Theology. In my own experience over thirty years of public involvement in Bioethics, I have discovered that the NNL approach has two overwhelming problems. What is offered to the secular dialogue, as an anthropocentric natural law, often sounds false to secular others because we propose something guided by our beliefs, but failing to acknowledge that contribution. However something that I have discovered latterly in that approach is in fact false by our own standards. By the strictures we impose on our contribution we in fact ignore the New Law instituted by Christ, the law of love. The New Natural Law (NNL) Project has proved to be a failure where it has been tried, and, I know realize, was doomed from the outset, because in being anthropocentric it was essentially lacking and the answers that it gave to problems were often unsatisfactory because lacking love and the particular demand of needing to be capable of being oriented towards God, the God of love. The NNL approach tended to produce a casuistry that was too liberal and too lacking in understanding of the essential role that affectivity plays in our lives, created as we are in the imago dei, in the image and likeness of the God of love. Such a morality demands much more than anthropocentricism can demand. In recognizing these difficulties I propose instead a more pragmatic approach that reflects a partnership between Philosophy and Theology as espoused by the Second Vatican Council, and by Pope’s Benedict XVI and Pope John Paul II, and which engages the work of Alasdair MacIntyre and Servais Pinckaers. An approach that I have tried with some success in chairing government committees. (shrink)

Book review of Sharon Anderson-Gold, and Pablo Muchnik, "Kant's Anatomy of Evil", Cambridge: Cambridge University Press, 2010, Pp 251, ISBN 9780521514323.

The knower paradox states that the statement ‘We know that this statement is false’ leads to inconsistency. This article presents a fresh look at this paradox and some well-known solutions from the literature. Paul Égré discusses three possible solutions that modal provability logic provides for the paradox by surveying and comparing three different provability interpretations of modality, originally described by Skyrms, Anderson, and Solovay. In this article, some background is explained to clarify Égré’s solutions, all three of which (...) hinge on intricacies of provability logic and its arithmetical interpretations. To check whether Égré’s solutions are satisfactory, we use the criteria for solutions to paradoxes defined by Susan Haack and we propose some refinements of them. This article aims to describe to what extent the knower paradox can be solved using provability logic and to what extent the solutions proposed in the literature satisfy Haack’s criteria. Finally, the article offers some reflections on the relation between knowledge, proof, and provability, as inspired by the knower paradox and its solutions. (shrink)

Centripetalism is often perceived as a type of a political system for a multi-segmental, especially multi-ethnic, country in order to create among the members of the political elite of moderate, accomodative, and integrative political behavior cross-cutting segmental divisions which, reaching beyond group interests, depoliticize the segmental separateness and, in this manner, reduce their significance. One of the central institutions of centripetalism is decentralization leading to a division of large segments into smaller parts that inhabit different, ideally multi-segmental regions, thus inclining (...) regional political elites of different segments to collaborate. Although both Nigeria and Indonesia have similar centripetal territorial structures, only Nigeria is a federation. This paper focuses on Nigerian centripetal federalism and its link to the so-called federal character principle that is mostly consociational in substance. Krzysztof Trzcinski, Centripetal Federalism, in: 50 Shades of Federalism, ed. by Soeren Keil & Paul Anderson, Canterbury: Canterbury Christ Church University & Montréal: CRÉQC, 2020. (shrink)

This paper aims to reconstruct the politico-philosophical content of the Ancient Wenzi, according to three interrelated questions: How does the text communicate its views to the reader? What are its main ideas? When and where were these ideas first put to writing? Accordingly, after a discussion of preliminaria in section 1, section 2 focuses on the rhetorical devices in the text, section 3 on its key terms, and section 4 on its possible historical context. The goal of this paper is (...) not only to describe the content of the Ancient Wenzi, but also to contextualize it. That is, to explore the debate to which the Ancient Wenzi may have responded. (shrink)

This paper is intended as a gateway to two 2000-year-old manuscripts of the Analects. The first two sections discuss the archaeological context of the discoveries and analyse the manuscripts themselves, including characteristic features of the bamboo strips and the texts inked thereon and notable differences between these and other Analects versions. In these sections, I also critically evaluate present-day Analects studies and offer alternative hypotheses where there is room for debate. The third and final section of the paper discusses what (...) I consider the most fascinating (and most complex) issue regarding the manuscripts: their provenance. In that section, I examine when, where, and why the Analects was copied onto the bamboo strips. The ultimate goal of this paper is to present a nuanced understanding of the two bamboo manuscripts that conveys the fascinating insights they offer while also exploring the limitations of what these manuscripts can actually tell us. (shrink)

Systematicity theory—developed and articulated by Paul Hoyningen-Huene—and scientific realism constitute separate encompassing and empirical accounts of the nature of science. Standard scientific realism asserts the axiological thesis that science seeks truth and the epistemological thesis that we can justifiably believe our successful theories at least approximate that aim. By contrast, questions pertaining to truth are left “outside” systematicity theory’s “intended scope” ; the scientific realism debate is “simply not” its “focus”. However, given the continued centrality of that debate in (...) the general philosophy of science literature, and given that scientific realists also endeavor to provide an encompassing empirical account of science, I suggest that these two contemporary accounts have much to offer one another. Overlap for launching a discussion of their relations can be found in Nicholas Rescher’s work. Following through on a hint from Rescher, I embrace a non-epistemic, purely axiological scientific realism—what I have called, Socratic scientific realism. And, bracketing the realist’s epistemological thesis, I put forward the axiological tenet of scientific realism as a needed supplement to systematicity theory. There are two broad components to doing this. First, I seek to make clear that axiological realism and systematicity theory accord with one another. Toward that end, after addressing Hoyningen-Huene’s concerns about axiological analysis, I articulate a refined axiological realist meta-hypothesis: it is, in short, that the end toward which scientific inquiry is directed is an increase in a specific subclass of true claims. I then identify a key feature of scientific inquiry, not generally flagged explicitly, that I take to stand as shared terrain for the two empirical meta-hypotheses. And I argue that this feature can be informatively accounted for by my axiological meta-hypothesis. The second broad component goes beyond mere compatibility between the two positions: I argue that, in want of a systematic account of science, we are prompted to find an end toward which scientific inquiry is directed that is deeper than what systematicity theory offers. Specifically, I argue that my refined axiological realist meta-hypothesis is required to both explain and justify key dimensions of systematicity in science. To the quick question, what is it that the scientific enterprise is systematically doing? My quick answer is that it is systematically seeking to increase a particular subclass of true claims. (shrink)

Early Chinese thought enjoys a wide appeal, in the scholarly world as much as elsewhere, as people are keen on learning about the ideas of Confucius, Mencius, and other thinkers whose views have shaped traditional Chinese culture. In the study of early Chinese thought, emphasis has long been on what thinkers said, not on how they proffered their views. Even studies that do consider the how, tend to focus on logic and argumentation, rather than rhetoric. Fortunately, in the past few (...) decades growing attention has been paid to Chinese rhetoric which has led to an impressive number of publications. This work briefly outlines rhetoric in the West and in China. (shrink)

Proponents of public reason views hold that the exercise of political power ought to be acceptable to all reasonable citizens. This article elucidates the common structure shared by all public reason views, first by identifying a set of questions that all such views must answer and, second, by showing that the answers to these questions stand in a particular relationship to each other. In particular, we show that what we call the ‘rationale question’ is fundamental. This fact, and the common (...) structure more generally, are often overlooked or distorted within the literature. As a result, we argue, several prominent argumentative moves made by both critics and defenders of public reason are unsuccessful. Our overall conclusion is that discussions of public reason views would be more fruitful if they made consistent use of the common structure we identify. (shrink)

The increasing workplace use of artificially intelligent (AI) technologies has implications for the experience of meaningful human work. Meaningful work refers to the perception that one’s work has worth, significance, or a higher purpose. The development and organisational deployment of AI is accelerating, but the ways in which this will support or diminish opportunities for meaningful work and the ethical implications of these changes remain under-explored. This conceptual paper is positioned at the intersection of the meaningful work and ethical AI (...) literatures and offers a detailed assessment of the ways in which the deployment of AI can enhance or diminish employees’ experiences of meaningful work. We first outline the nature of meaningful work and draw on philosophical and business ethics accounts to establish its ethical importance. We then explore the impacts of three paths of AI deployment (replacing some tasks, ‘tending the machine’, and amplifying human skills) across five dimensions constituting a holistic account of meaningful work, and finally assess the ethical implications. In doing so we help to contextualise the meaningful work literature for the era of AI, extend the ethical AI literature into the workplace, and conclude with a range of practical implications and future research directions. (shrink)

Public shaming plays an important role in upholding valuable social norms. But, under what conditions, if any, is it morally justifiable? Our aim in this paper is systemically to investigate the morality of public shaming, so as to provide an answer to this neglected question. We develop an overarching framework for assessing the justifiability of this practice, which shows that, while shaming can sometimes be morally justifiable, it very often is not. In turn, our framework highlights several reasons to be (...) concerned about the increasingly widespread phenomenon of online public shaming. (shrink)

Overview of fundamental work in deontic logic.

We are witnessing increasing use of the Internet, particular social media, to criticize (perceived or actual) moral failings and misdemeanors. This phenomenon of so-called ‘online public shaming’ could provide a powerful tool for reinforcing valuable social norms. But it also threatens unwarranted and severe punishments meted out by online mobs. This paper analyses the dangers associated with the informal enforcement of norms, drawing on Locke, but also highlights its promise, drawing on recent discussions of social norms. We then consider two (...) crucial conditions that online public shaming must meet in order to be justifiable: proportionality and accountability. We argue that these requirements are in fact frequently violated, rendering most cases of online public shaming unjustified. While the use of online public shaming against others’ vices has some apparent virtues, it is currently rarely justified, given its own vices. (shrink)

This paper introduces constitutivism about practical reason, which is the view that we can justify certain normative claims by showing that agents become committed to these claims simply in virtue of acting. According to this view, action has a certain structural feature – a constitutive aim, principle, or standard – that both constitutes events as actions and generates a standard of assessment for action. We can use this standard of assessment to derive normative claims. In short, the authority of certain (...) normative claims arises from the bare fact that we are agents. This essay explains the constitutivst strategy, surveys the extant attempts to generate constitutivist theories, and considers the problems and prospects for the theory. (shrink)

In certain cases, people judge that agents bring about ends intentionally but also that they do not bring about the means that brought about those ends intentionally—even though bringing about the ends and means is just as likely. We call this difference in judgments the Kraemer effect. We offer a novel explanation for this effect: a perceived difference in the extent to which agents know how to bring about the means and the ends explains the Kraemer effect. In several experiments, (...) we replicate the Kraemer effect in a variety of non-moral and moral scenarios, and we find support for our new account. This work accords with a burgeoning area of action theory that identifies an important connection between know-how and intentionality. (shrink)

Public reason views hold that the exercise of political power must be acceptable to all reasonable citizens. A growing number of philosophers argue that this reasonable acceptability principle (RAP) can be justified by appealing to the value of civic friendship. They claim that a valuable form of political community can only be achieved among the citizens of pluralistic societies if they refrain from appealing to controversial ideals and values when justifying the exercise of political power to one another. This paper (...) argues against such accounts. In order to justify RAP, one must explain and defend a conception of reasonableness. Civic friendship is unfit to perform this task, rendering it unable to ground public reason alone. Meanwhile, pluralist views that combine civic friendship with other considerations in order to specify RAP either fail or make civic friendship a spare wheel in the argument for public reason. (shrink)

In the last decades, several attempts were made to exploit the relatedness between the early analytic philosophers and Hegel. Some 30 years ago, Peter Hylton and Nicholas Griffin investigated the apprenticeship of Bertrand Russell with neo-Hegelians. 25 years later, the direction of interest changed. Paul Redding and Angelica Nuzzo sought a connection between Hegel and analytic philosophy following hints made by Robert Brandom and John McDowell. According to these authors, Hegel can be seen as a theorist of concepts. (...) Moreover, they found that Hegel’s understanding of concepts is close to that of the early analytic philosophy. The approach we are following in this paper is different. We shall concentrate on the relatedness between the method of the early analytic philosophers and aspects of Hegel’s method. This is an unexplored venue and we hope that our study will open a new perspective both in the history of the early analytic philosophy and in Hegel Studies. To be more explicit, we are not going to specifically investigate the genealogical connection between these two methods. We shall be mainly concerned with their kinship. (shrink)

What, if anything, is fanaticism? Philosophers including Locke, Hume, Shaftesbury, and Kant offered an account of fanaticism, analyzing it as (1) unwavering commitment to an ideal, together with (2) unwillingness to subject the ideal (or its premises) to rational critique and (3) the presumption of a non-rational sanction for the ideal. In the first part of the paper, I explain this account and argue that it does not succeed: among other things, it entails that a paradigmatically peaceful and tolerant individual (...) can be a fanatic. The following sections argue that the fanatic is distinguished by four features: (4) the adoption of sacred values; (5) the need to treat these values as unconditional in order to preserve a particular form of psychic unity; (6) the sense that the status of these values is threatened by lack of widespread acceptance; and (7) the identification with a group, where the group is defined by shared commitment to the sacred values. If the account succeeds, it not only reveals the nature of fanaticism, but also uncovers a distinctive form of ethical critique: we can critique a way of understanding values not on the grounds that it is false, but on the grounds that it promotes a particular form of social pathology. (shrink)

On the standard interpretation, if a person holds cyclical preferences, the person is prone to acting irrationally. I provide a different interpretation, tying cyclical preferences not to irrationality, but to indecision. According to this alternative understanding – coined the indecision interpretation – top cycles in a person’s preferences can be associated with a difficulty in justifying one’s choice. If an agent’s justificatory impasse persists despite attempts to resolve the cycle, the agent can be deemed undecided. The indecision interpretation is compatible (...) with the standard interpretation of such cycles as instances of irrationality. Yet indecision corresponds to a first-person, non-instrumental perspective on the problem, whereas irrationality usually corresponds to a third-person, instrumental perspective. Due to these differences, interpreting cycles in terms of indecision offers a novel conceptual perspective, pertinent both for explanatory purposes and for the aim of normative theorizing. (shrink)

Among recent objections to Pascal's Wager, two are especially compelling. The first is that decision theory, and specifically the requirement of maximizing expected utility, is incompatible with infinite utility values. The second is that even if infinite utility values are admitted, the argument of the Wager is invalid provided that we allow mixed strategies. Furthermore, Hájek has shown that reformulations of Pascal's Wager that address these criticisms inevitably lead to arguments that are philosophically unsatisfying and historically unfaithful. Both the objections (...) and Hájek's philosophical worries disappear, however, if we represent our preferences using relative utilities rather than a one-place utility function. Relative utilities provide a conservative way to make sense of infinite value that preserves the familiar equation of rationality with the maximization of expected utility. They also provide a means of investigating a broader class of problems related to the Wager. (shrink)

DESENVOLVIMENTO EMBRIONÁRIO E DIFERENCIAÇÃO SEXUAL -/- E. I. C. da Silva Departamento de Agropecuária – IFPE Campus Belo Jardim Departamento de Zootecnia – UFRPE sede -/- 1.1 INTRODUÇÃO O sexo foi definido como a soma das diferenças morfológicas, fisiológicas e psicológicas que distinguem o macho da fêmea permitindo a reprodução sexual e assegurando a continuidade das espécies. Os processos de diferenciação sexual são realizados durante o desenvolvimento embrionário, onde ocorre a proliferação, diferenciação e maturação das células germinativas e primordiais, precursoras (...) de ovócitos e espermatozoides em fêmeas e machos, respectivamente. Assim, os embriões machos e fêmeas iniciam o seu desenvolvimento de forma semelhante, de modo que em ambos os sexos se estabelecem em estruturas idênticas a partir das quais se formarão os órgãos reprodutores correspondentes a cada sexo. O conhecimento da origem e do desenvolvimento do aparelho genital é indispensável para entender sua função e as alterações que produzem infertilidade ou esterilidade. 1.2 DETERMINAÇÃO DO SEXO CROMOSSÔMICO Nos mamíferos, o sexo cromossômico é determinado no momento da fertilização, quando um óvulo, que contém um cromossomo X, é fecundado por um espermatozoide portador de um cromossomo X ou um cromossomo Y. No primeiro caso, o complemento cromossômico seria XX, o que originaria uma fêmea (sexo homogamético), e no segundo daria como resultado um macho com a fórmula cromossômica XY (sexo heterogâmico). 1.3 A GÔNADA INDIFERENCIADA A primeira manifestação das gônadas se aprecia no embrião em forma de um par de eminências longitudinais chamadas cristas ou dobras gonodais, situadas em ambos os lados da linha média entre os mesonefros (rins em desenvolvimento) e do mesentério dorsal. Nos embriões dos mamíferos, as células germinativas primordiais (CGP) manifestam-se em estágios precoces do desenvolvimento, podendo ser detectadas pela primeira vez na metade da gastrulação. As CGP são células grandes, de citoplasma claro e núcleo grande e redondo, localizadas na parede do saco vitelino, perto do alantoide. Essas células possuem grande capacidade de proliferação e vão migrar desde o endoderma do intestino e o epitélio do saco vitelino, através do mesentério, até as cristas gonodais. Isso ocorre por volta do 26° dia da gestação no bovino. Sua migração realiza-se graças aos movimentos de translocação passiva e deslocamento ameboide ativo. Desconhece-se o mecanismo pelo qual estas células são dirigidas para as cristas gonodais, porém foram estudadas algumas moléculas que se expressam durante sua migração e que poderiam desempenhar um papel importante na diferenciação deste tipo celular. A fosfatase alcalina é uma enzima que tem sido usada como marcador de CGP para determinar a sua origem e migração. Num estudo recente, foi inserido um marcador fluorescente que se exprime unicamente nas células germinativas primordiais de embriões transgênicos, e utilizando este marcador e a fosfatase alcalina determinou-se a origem e o padrão de migração destas células. O primeiro sinal de diferenciação das células germinativas primordiais é a expressão de fosfatase alcalina, e esta apareceu pela primeira vez na parte mais posterior da linha primitiva. No sétimo dia de desenvolvimento no embrião do camundongo, o endoderma visceral (AF+) é substituído pelo endoderma definitivo (AF-) originado na parte anterior da linha primitiva. O fator de transcrição Oct-4 é expresso nas CGP de ambos os sexos, pelo que acredita-se estar envolvido na mantença a totipotêncialidade das células. O receptor tirosina quinase, cujo ligante é o fator de Steel, é outra das moléculas que expressam as CGP. Tem sido demonstrado que este receptor possui um papel muito importante na sobrevivência deste tipo celular. Existem outros fatores que promovem a sobrevivência e/ou proliferação de CGP in vitro. Em experiências realizadas com o fator de transformação beta I (TGFβ-I), observou-se que este tem um efeito negativo sobre a proliferação das CGP. Outra atividade que tem sido postulada a este fator é o de um agente quimioatraente que possivelmente possa direcionar a migração destas células para a gônada. a) Um formado pelas células germinativas primordiais (precursoras dos gametas masculinos ou femininos), rodeadas de células somáticas das quais posteriormente se derivarão as células de Sertoli no macho e as células da granulosa na fêmea. b) O tecido que formará o estroma da gônada: tecido conjuntivo, vasos sanguíneos e as células intersticiais com atividade esteroidogênica (células de Leydig no testículo e a teca interna do ovário). As células somáticas do primórdio gonodal originam-se do mesoderma. Inicialmente são de três tipos: mesenquimáticas, mesoteliais e endoteliais. As células mesenquimáticas e mesoteliais iniciam grande atividade proliferativa ao chegar as CGP. Observa-se então uma condensação de células de origem mesotelial e mesenquimatoso que forma um agregado compacto denominado "blastema gonodal". A partir deste primórdio embrionário, diferenciam-se dois tecidos gonodais: os cordões sexuais e o estroma. Os cordões sexuais são arranjos epiteliais que se encontram delimitados por uma folha basal, e dentro deles encontramos as CGP. Por sua vez, no estroma encontram-se células do tipo mesenquimático e vasos sanguíneos. Neste momento, as gônadas são indiferenciadas e bipotencialmente sexuais, sendo impossível diferenciar, morfologicamente, uma gônada masculina de uma feminina, mas no caso dos machos genéticos já existe uma diferenciação da gônada a nível molecular. Nesta fase já se encontram presentes as estruturas das quais se desenvolvem os dutos mesonéfricos ou de Wolff precursores do aparelho genital masculino e os dutos paramesonéfricos ou de Müller que darão origem ao aparelho reprodutor feminino. Há uma série de fatores envolvidos no desenvolvimento precoce da gônada, entre os quais o fator esteroidogênico I (SFI: Steroidogenic fator l), que é um membro da subfamília de receptores nucleares, receptores órfãos. Este fator de transcrição tem um local de ligação ao DNA composto por dois dedos-de-Zinc. O SFI foi identificado como um ativador de genes envolvidos na biossíntese de esteroides em diferentes células. O SFI está presente durante o desenvolvimento embrionário em regiões associadas com funções endócrinas como gônadas, adrenais, pituitárias e hipotálamos. Os animais homozigotos para o gene SFI defeituoso, necessitam de gônadas e adrenais e têm a função gonadotrófica alterada. Os ratos sem SFI carecem de gonadotrofos e têm um desenvolvimento anormal do núcleo ventro-medial do hipotálamo; em particular as gônadas deixam de se desenvolver entre os dias 11 a 15 e degeneram-se por apoptose. No entanto, a crista genital forma-se e é colonizada pelas células germinativas, o que indica que estas continuam a receber o sinal adequado para a sua migração. Portanto, o SFI não está envolvido no desenvolvimento precoce da gônada e do sistema urogenital, mas parece estar envolvido na manutenção do crescimento das células somáticas presentes na gônada indiferenciada. O gene associado ao tumor de Wilms (WTI: Wilm's tumor Associated) está envolvido no desenvolvimento da gônada e do rim. Durante o desenvolvimento embrionário, WTI se expressa em todo o mesoderma intermediário e posteriormente na gônada indiferenciada, bem como no rim em formação. WTI regula o sinal indutivo do mesênquima para o epitélio celômico dos mesonefros. Se este for o caso, então WTI é responsável pelo crescimento da crista genital ao dirigir a entrada do epitélio celômico. Dado que estas células darão origem às células de Sertoli, a carência de WTI pode causar o desenvolvimento de embriões XY como fêmeas simplesmente porque não se formam as células de Sertoli. Em geral, todos os genes importantes na diferenciação do mesoderma intermediário e do sistema urogenital intervêm no desenvolvimento da gônada precoce. 1.4 DIFERENCIAÇÃO GONODAL O desenvolvimento das gônadas e ductos genitais descritos até o momento, é o mesmo para ambos os sexos. Igualmente, os genes descritos, que estão envolvidos no desenvolvimento das gônadas, ductos genitais e migração das células germinativas, afetam igualmente os embriões com genótipo XX ou XY. A gônada primitiva consiste anatomicamente de uma medula (interna) e uma crosta (externa), e de acordo com o local onde ocorre a colonização das células germinativas, diferenciara em testículo ou um ovário, respectivamente. Nos mamíferos, a primeira manifestação estrutural de diferenciação sexual é detectada na gônada dos machos, onde as células germinativas estão localizadas na medula. A diferenciação do testículo inicia-se quando os cordões sexuais se separam do epitélio celômico como consequência dos arranjos produzidos por uma invasão do mesênquima e vasos sanguíneos que provoca a compactação dos cordões, agora denominados cordões testiculares. As células que rodeiam os cordões se achatam e formam as células mioides, que são responsáveis pela formação das membranas basais. As células do epitélio interno, ou seja, as células de Sertoli, têm duas funções principais: o suporte das CGP e a síntese da hormona antimulleriana, responsável pela regressão dos ductos de Müller e secretada durante o período de diferenciação sexual. As células do estroma que rodeiam os cordões testiculares diferenciam-se para formar vários tipos de células: células mioides, fibroblastos, endotélio e células de Leydig, que são as mais importantes pela sua atividade endócrina. Posteriormente, os cordões testiculares dão origem aos túbulos seminíferos, que contêm o epitélio que produzirá os espermatozoides ao chegar à puberdade. Na fêmea, durante os estágios iniciais de diferenciação gonodal, não se observam mudanças em relação à gônada indiferenciada, só pode-se observar um certo crescimento devido à proliferação de células somáticas e germinativas. As células germinativas iniciam um período de proliferação, que termina com o início da meiose. Iniciada a meiose, dá-se o processo de foliculogênese; neste momento os cordões epiteliais se fragmentam, de tal maneira que cada ovócito fica rodeado de células epiteliais cobertas por uma folha basal fina (figura 1). Para que a gônada primitiva se desenvolva em testículo é indispensável a presença do cromossoma Y, independentemente do número de cromossomas X que contenha o genoma de um indivíduo. O gene determinante do testículo encontra-se localizado no cromossoma Y, denominado sry em ratos e SRY em humanos. O gene sry se expressa durante o desenvolvimento embrionário na crista genital de embriões de camundongos. A expressão é detectável no dia 10,5, pouco depois do aparecimento das cristas genitais, atinge o seu máximo durante o dia 11,5 e mantém-se até pouco depois de ocorrerem os primeiros sinais morfológicos de diferenciação testicular no dia 12,5. Este padrão de expressão é compatível com a teoria de que sry atua induzindo a ativação dos genes (figura 2) que conduzem ao desenvolvimento testicular, sem que exista a necessidade da expressão contínua de sry para manter a diferenciação do testículo após o dia 12,5. Como mencionado anteriormente, a gônada primitiva é composta por vários tipos de células. No entanto, as células germinativas primordiais não são o local de expressão do sry, já que os embriões que necessitam de células germinativas mantêm a expressão de sry e desenvolvem o sexo gonodal normalmente. As células somáticas na gônada em desenvolvimento incluem também as células de suporte. Sabe-se que é nestas células que o sry é expresso para que se diferenciem em células de Sertoli, e a expressão transitória de sry indica que deve ativar a outros genes para a manutenção das células de Sertoli. Uma vez diferenciadas as células de Sertoli, elas se encarregarão da diferenciação do resto das células na gônada. -/- Figura 1: Representação da diferenciação dos órgãos genitais internos. Adaptado de BRONSON, 1989. Figura 2: Cascada de genes envolvidos na diferenciação sexual, adaptado de KOOPMAN, 1999. O fator sry é necessário para a diferenciação do testículo. Embora não se conheçam os genes que provavelmente regulam esse gene, estudos realizados em camundongos demonstram que este gene parece coordenar-se com certos genes autossômicos. Entre estes genes autossômicos, o sox9, que é produzido pelas células de Sertoli uma vez que são estimuladas por sry, de modo que sox9 é um dos genes relacionados estruturalmente com sry. O Sox9 funciona como um fator de transcrição, mas não se sabe se a proteína tem qualquer outra função estrutural; este gene exprime-se abundantemente nos condrócitos e está relacionado com defeitos do aparelho ósseo chamados displasia campomélica. Curiosamente, os pacientes XY com esta condição sofrem frequentemente de reversão do sexo. O Sox9 é um dos poucos genes, além do SRY, do qual as mutações demonstraram interferir com a determinação sexual masculina. No entanto, apenas 75% dos pacientes com anomalias esqueléticas de tipo displasia campomélica têm reversão sexual e não foram encontrados casos de reversão sexual devido a um defeito de Sox9 que não seja acompanhado de defeitos esqueléticos. Isso indica que o Sox9 é apenas um membro da rede de genes que são ativados para determinar a diferenciação sexual, enquanto a rota que rege a condrogênese é mais sensível a perturbações deste. O momento em que se detecta a expressão do gene Sox9 (11dpc em ratos) coincide com a máxima expressão de sry, o que poderia indicar a possibilidade de que sry regule positivamente a Sox9. De fato, na região do promotor de Sox9 há um local de união ao que potencialmente se pode unir o sry. A expressão de Sox9 durante a diferenciação sexual sugere um papel abaixo de sry na diferenciação das células de Sertoli. O cromossoma X também é importante na diferenciação gonodal. O gene DAX-I foi isolado do lócus DSS (Dosage sensitive sex reversal) do cromossoma X. DAX-I é parte da cascata de determinação sexual, mas não é necessário para a formação do testículo. DAX-I é um membro dos receptores nucleares conhecidos como receptores órfãos. Este gene demonstrou ser um poderoso repressor da transcrição de SFI e de vários genes. Os padrões de expressão de DAX-I são complementares daqueles de SFI, ambos expressos nas cristas genitais. Em resumo, dada a evidência exposta, desenvolveu-se a hipótese de que DAX-I é um antagonista de sry; esse antagonismo é dependente dos níveis relativos de DAX-I e sry e de um limiar que varia de espécie para espécie. A DAX-I foi classificada como o gene antitestículo. Na fêmea (cariótipo XX) é importante que ocorra a inativação de um dos cromossomas sexuais X para que se mantenha o equilíbrio genético ao igualar o conteúdo de DNA dos cromossomas. Esse cromossoma inativado constitui o chamado corpúsculo de Barr. No entanto, para que a meiose se realize, é necessário dos dois cromossomas X ativos nos ovócitos para assegurar a diferenciação ovárica e a fertilidade. 1.5 DIFERENCIAÇÃO DOS DUCTOS SEXUAIS O embrião possui, além das gônadas indiferenciadas, dois sistemas de ductos: os de potencialidade masculina denominam-se ductos de Wolff ou mesonéfricos, e os de potencialidade feminina se chamam ductos de Müller ou paramesonéfricos (figura 1). Se a diferenciação gonodal levou à formação de um testículo, a partir do ducto mesonéfrico ou de Wolff se desenvolverão os ductos eferentes, o epidídimo, os ductos deferentes e as vesículas seminais. As hormonas importantes no desenvolvimento do aparelho genital masculino são a testosterona, produzida pelas células de Leydig, e sua forma 5α reduzida, a 5α di-hidrotestosterona. Acredita-se que a testosterona é responsável pela virilização dos ductos de Wolff, e a di-hidrotestosterona dos órgãos genitais externos. No macho, os canais de Müller atrofiam-se devido à ação de uma hormona fetal de origem testicular denominada hormona inibidora das estruturas de Müller (HIM) ou hormona antimulleriana. Este processo começa assim que os cordões espermáticos se formam e se diferenciam as células de Sertoli. A existência de HIM foi proposta baseada em estudos realizados em bezerras freemartin, devido à existência de uma hormona responsável pela atresia dos ductos de Müller que na fêmea dá origem ao útero e aos ovidutos. Essa hormona provoca a involução do aparelho genital do bovino nas gestações gemelares nas quais os produtos de diferente sexo têm comunicação sanguínea por ter ocorrido a anastomose dos vasos de ambas as placentas (figura 3). A HIM é uma glicoproteína pertencente à subfamília de TGFβ, é expressa pelas células que darão origem às células de Sertoli e é um dos primeiros marcadores de diferenciação nestas células. A HIM é secretada na vida adulta pelas células de Sertoli no testículo e por células da granulosa no ovário. No rato a HIM é expressa-se no 12° dia em um teste padrão que segue muito de perto o aumento na expressão de sry. No macho, esta secreção de HIM continua durante a vida fetal e adulta, contudo os níveis de HIM declinam na puberdade devido a um aumento na secreção de testosterona. Vários fatores intervêm na regulação do gene de HIM, incluindo os acima descritos SFI e Sox9. O gene HIM contém segmentos de DNA que são conservados em várias espécies de vertebrados. Existe um nexo de ligação para SFI, que ativa a transcrição de HIM. A mutação no local de ligação de SFI resulta em reversão do sexo em indivíduos XY incluindo genitais femininos normais, presença de um útero formado enfatizando a importância de SFI na determinação sexual e na expressão de HIM. Embora SFI seja um bom candidato como regulador de HIM, é expresso em outras células, como as de Leydig e adrenais, que não expressam HIM. Em contrapartida, Sox9 é expresso unicamente nas células de Sertoli que são as produtoras de HIM. O gene HIM também tem um nexo de ligação para Sox9. Além disso, Sox9 pode atuar sinergicamente com SFI para promover a secreção de HIM. Ao contrário destes dois fatores de transcrição, DAX-I antagoniza a ação de Sox9 e provavelmente SFI sobre o promotor de HIM. Assim, para que as células de Sertoli secretem HIM, a transcrição de DAX-I deve diminuir. Figura 3: Representação da diferenciação dos órgãos genitais externos. Adaptado de BRONSON, 1989. Os ductos de Wolff tornam-se o sistema de ejaculação do macho. A porção mais próxima dos testículos dá origem ao epidídimo, a parte central ao ducto deferente e a porção mais distal às vesículas seminais. A próstata e a parte membranosa da uretra do macho desenvolvem-se a partir da porção pélvica do seio urogenital. A virilização e diferenciação dos ductos de Wolff dependem da produção de testosterona pelo testículo. Quanto aos órgãos genitais externos do macho, o tubérculo genital é ampliado e as dobras uretrais se fundem para formar a uretra peniana. A fusão das dobras uretrais aproxima os tubérculos genitais para formar o escroto (figura 4). Figura 4: Diferenciação do aparelho genital da fêmea e do macho. Adaptado de KOOPMAN, 1989. A diferenciação dos órgãos genitais da fêmea ocorre de forma passiva, já que a ausência de testículos e por isso da hormona inibidora dos ductos de Müller (HIM), assim como dos andrógenos virilizantes, favorece o desenvolvimento dos ductos de Müller, enquanto os de Wolff sofrem atrofia. A porção cefálica dos ductos de Müller dá origem aos ovidutos, que na sua terminação caudal se fundem com o útero. O contato dos ductos de Müller com o seio urogenital induz uma intensa proliferação celular que resulta na formação da área uterovaginal localizado entre o seio urogenital e os ductos de Müller. As células do prato uterovaginal proliferam e aumentam a distância entre as duas estruturas criando o espaço que formará a vagina quando o prato é canalizado e forma um lúmen. Em contraste com o que ocorre no macho, na fêmea a maior parte do seio urogenital se mantém exposta na superfície da abertura onde desembocam a vagina e a uretra. O tubérculo urogenital da fêmea tem um crescimento limitado e forma o clitóris. A sequência de passos da diferenciação sexual do aparelho genital é resumida na tabela 1. Tabela 1: Destino em desenvolvimento dos rudimentos sexuais dos fetos macho e fêmea dos mamíferos -/- Rudimento sexual Macho Fêmea Gônada Testículo Ovário Ductos de Müller (Paramesonéfricos) Vestígios Útero, parte da vagina, ovidutos Ductos de Wolff (Mesonéfricos) Ductos eferentes deferentes, epidídimo, vesículas seminais Vestígios Seio urogenital Uretra, próstata, glândulas bulbouretrais Parte da vagina, uretra, vestíbulo, glândulas vestibulares Tubérculo genital Pênis Clitóris Pregas vestibulares Escroto Lábios vulvares Fonte: HAFEZ, 2004. 1.6 DIFERENCIAÇÃO SEXUAL DO HIPOTÁLAMO Os processos de diferenciação sexual não se limitam apenas às células somáticas do organismo do feto, mas incluem também os centros nervosos superiores do cérebro. Assim, da mesma maneira que a gônada e os ductos sexuais se desenvolvem para o tipo feminino ou masculino, propôs-se que o cérebro pode ser "masculinizado" ou permanecer "Feminizado". A diferenciação do hipotálamo vai depender do ambiente esteroidal do neonato e ocorre na fase perinatal. Estes eventos serão de grande transcendência na vida reprodutiva do indivíduo. Tanto a fêmea como o macho nascem com a capacidade de secreção de gonadotropinas de acordo com um padrão cíclico; contudo, no macho, a exposição do hipotálamo à ação dos andrógenos testiculares durante os primeiros dias da vida extrauterina provoca a masculinização, com o qual o hipotálamo do macho é programado para que a secreção de gonadotropinas se realize a um ritmo relativamente constante por parte da hipófise (secreção tônica). Na fêmea, tanto a secreção tônica como a cíclica se conservam. No entanto, observou-se que a injeção de testosterona ou o transplante de testículo na rata fêmea durante os primeiros dias de vida, suprime a sua futura atividade estral (secreção cíclica). Por outro lado, se os ovários forem transplantados para o rato macho normal castrado na idade adulta, o animal não desenvolve qualquer atividade cíclica, mas se os machos transplantados forem castrados ao nascer, o ovário é capaz de efetuar mudanças cíclicas e ovulações. Isto foi demonstrado em roedores, mas não em animais domésticos ou na espécie humana. Portanto, o padrão de secreção de gonadotropinas, seja cíclico ou tônico, não depende da hipófise, mas do hipotálamo e sua correta diferenciação. 1.7 CONCLUSÕES A maioria dos conhecimentos no campo da biologia do desenvolvimento e, muito especificamente, dos processos de diferenciação sexual têm sido originados de estudos relacionados com desordens congênitas, que na sua maioria devem-se a defeitos de genes específicos. A análise detalhada destas desordens permitiu entender alguns mecanismos endócrinos, moleculares e genéticos envolvidos na diferenciação sexual. A identificação do gene sry como determinante do testículo foi uma contribuição crucial e abriu as portas à compreensão dos mecanismos moleculares e celulares relacionados com o desenvolvimento do testículo. Se este gene não estiver presente, é criado um programa genético alternativo para levar a cabo a diferenciação gonodal para o ovário. Finalmente, devemos ter presente que é necessária uma correlação entre mudanças morfológicas e expressão de genes durante o desenvolvimento para entender os mecanismos relacionados com a diferenciação. -/- Apoio -/- Realização -/- REFERÊNCIAS BIBLIOGRÁFICAS ANDERSON, Robert et al. The onset of germ cell migration in the mouse embryo. Mechanisms of development, v. 91, n. 1-2, p. 61-68, 2000. AUSTIN, Colin Russell; SHORT, R. V. Reproduction in Mammals: Volume 1, Germ Cells and Fertilization. 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Mullerian inhibiting substance activity in bovine fetal, newborn and prepubertal testes. Biology of reproduction, v. 16, n. 2, p. 238-243, 1977. HAFEZ, Elsayed Saad Eldin; HAFEZ, B. Reprodução animal. São Paulo: Manole, 2004. HANLEY, Neil A. et al. Steroidogenic factor 1 (SF-1) is essential for ovarian development and function. Molecular and cellular endocrinology, v. 163, n. 1-2, p. 27-32, 2000. HIORT, Olaf; PAUL-MARTIN, H. The molecular basis of male sexual differentiation. European journal of endocrinology, v. 142, n. 2, p. 101-110, 2000. HOLY, Lubos; MARTÍNEZ JÚSTIZ, G. Colab. Biología de la reproducción bovina. Havana: Revolucionária, 1975. JOSSO, Nathalie et al. The role of anti-Müllerian hormone in gonadal development. Molecular and cellular endocrinology, v. 145, n. 1-2, p. 3-7, 1998. JOST, Alfred et al. Studies on sex differentiation in mammals. In: Proceedings of the 1972 Laurentian Hormone Conference. Londres: Academic Press, 1973. p. 1-41. KNOBIL, Ernst. Knobil and Neill's physiology of reproduction. EUA: Gulf Professional Publishing, 2006. KOFMAN ALFARO, S.; MERCHANT LARIOS, H.; PEREZ PALACIOS, G. Diferenciacion sexual. I. Bases biologicas del dimorfismo sexual. Rev. invest. clín, p. 349-59, 1982. KOOPMAN, Peter. Sry and Sox9: mammalian testis-determining genes. Cellular and Molecular Life Sciences CMLS, v. 55, n. 6-7, p. 839-856, 1999. MCDONALD, L. E. Veterinary endocrinology. Lea & Febiger, Philadelphia, Pa, 1969. MEIZEL, S.; JOHNSON, M. H. Development in mammals. MH Johnson, Ed, v. 3, p. 1-64, 1978. MELLO, Maricilda Palandi de; ASSUMPÇÃO, Juliana de G.; HACKEL, Christine. Genes envolvidos na determinação e diferenciação do sexo. Arquivos Brasileiros de Endocrinologia & Metabologia, v. 49, n. 1, p. 14-25, 2005. -/- REFERÊNCIAS BIBLIOGRÁFICAS MERCHANT-LARIOS, H. Ovarian differentiation. The Vertebrate Ovary, p. 47-81, 1978. MIES FILHO, Antonio. Reprodução dos animais. Porto Alegre: Sulina, 1987. NEF, Serge; PARADA, Luis F. Hormones in male sexual development. Genes & Development, v. 14, n. 24, p. 3075-3086, 2000. PARKER, Keith L.; SCHEDL, Andreas; SCHIMMER, Bernard P. Gene interactions in gonadal development. Annual review of physiology, v. 61, n. 1, p. 417-433, 1999. SWAIN, Amanda; LOVELL-BADGE, Robin. Mammalian sex determination: a molecular drama. Genes & development, v. 13, n. 7, p. 755-767, 1999. WILHELM, Dagmar; PALMER, Stephen; KOOPMAN, Peter. Sex determination and gonadal development in mammals. Physiological reviews, v. 87, n. 1, p. 1-28, 2007. WILSON, Jean D.; GRIFFIN, James E.; GEORGE, Fredrick W. Sexual differentiation: early hormone synthesis and action. Biology of reproduction, v. 22, n. 1, p. 9-17, 1980. -/- Emanuel Isaque Cordeiro da Silva Belo Jardim, 07 de Maio de 2020. (shrink)

Debates between political liberals and liberal perfectionists have been reinvigorated by Jonathan Quong’s Liberalism Without Perfection. In this paper I argue that certain forms of perfectionism can rebut or evade Quong’s three central objections – that perfectionism is manipulative, paternalistic, and illegitimate. I then argue that perfectionists can defend an ‘internal conception’ of perfectionism, parallel in structure to Quong’s ’internal conception’ of political liberalism, but with a different conception of the justificatory constituency. None of Quong’s arguments show that his view (...) should be preferred to this perfectionist internal conception. It can thus equally claim to achieve ‘justification to all reasonable citizens’. (shrink)

Andrew Lister’s Public Reason and Political Community is an important new contribution to the debate over political liberalism. In this article, I critically evaluate some of the central arguments of the book in order to assess the current state of public reason liberalism. I pursue two main objections to Lister’s work. First, Lister’s justification for public reason, which appeals to the value of civic friendship, fails to show why public reason liberalism should be preferred to an alternative democratic theory that (...) does not include public reason restrictions. Second, there are several important ambiguities and tensions within Lister’s view that he does not adequately resolve. His approach to them often takes public reason liberalism in directions that many of its advocates will reject. More work thus remains to be done by public reason liberals both to show why public reason restrictions are necessary and to resolve these tensions in a more satisfactory way. (shrink)

According to cognitive psychologists, moral decision-making is a dual-process phenomenon involving two types of cognitive processes: explicit reasoning and implicit intuition. Moral development involves training and integrating both types of cognitive processes through a mix of instruction, practice, and reflection. Serious games are an ideal platform for this kind of moral training, as they provide safe spaces for exploring difficult moral problems and practicing the skills necessary to resolve them. In this article, we present Morality Play, a model for the (...) design of serious games for ethical expertise development based on the Integrative Ethical Education framework from moral psychology and the Lens of the Toy model for serious game design. (shrink)

According to political liberalism, laws must be justified to all citizens in order to be legitimate. Most political liberals have taken this to mean that laws must be justified by appeal to a specific class of ‘public reasons’, which all citizens can accept. In this paper I defend an alternative, convergence, model of public justification, according to which laws can be justified to different citizens by different reasons, including reasons grounded in their comprehensive doctrines. I consider three objections to such (...) an account—that it undermines sincerity in public reason, that it underestimates the importance of shared values, and that it is insufficiently deliberative—and argue that convergence justifications are resilient to these objections. They should therefore be included within a theory of political liberalism, as a legitimate form of public justification. This has important implications for the obligations that political liberalism places upon citizens in their public deliberations and reason-giving, and might make the theory more attractive to some of its critics, particularly those sympathetic to religious belief. (shrink)

The standard analysis of supererogation is that of optional actions that are praiseworthy to perform, but not blameworthy to skip. Widespread assumptions are that action beyond the call is at least necessarily equivalent to supererogation ("The Equivalence") and that forgoing certain agent-favoring prerogatives entails supererogation (“The Corollary”). I argue that the classical conception of supererogation is not reconcilable with the Equivalence or the Corollary, and that the classical analysis of supererogation is seriously defective. I sketch an enriched conceptual scheme, “Doing (...) Well Enough (DWE)”, that allows for distinct analyses of action beyond the call and supererogation, among other often neglected fundamental moral notions. Parallels and asymmetries with suberogation are briefly explored. Apparently, DWE’s core act-evaluative notions are more fundamental than the agent-evaluative ones of supererogation/suberogation. (shrink)

The current political climate is awash with groups that we might be tempted to label irrational, extremist, hyper-partisan; it is full of echo-chambers, radicalization, and epistemic bubbles. Philosophers have profitably analyzed some of these phenomena. In this essay, I draw attention to a crucial but neglected aspect of our time: the way in which certain groups are fanatical. I distinguish fanatical groups from other types of problematic groups, such as extremist and cultish groups. I argue that a group qualifies as (...) fanatical only if it has features that promote individual fanaticism. But how might a group promote individual fanaticism? I argue that a typical feature of fanatical groups is their tendency to encourage an emotion that philosophers sometimes call “ressentiment,” which differs from ordinary resentment. I explain what ressentiment is, how it can be fostered, and how it can lead to fanaticism. I contend that this account helps us to identify a disturbing and increasingly widespread feature of contemporary social and political groups. (shrink)

Appears to give the first model-theoretic account of both "must" and "ought" (without conflating them with one another). Some key pre-theoretic semantic and pragmatic phenomena that support a negative answer to the main title question are identified and a conclusion of some significance is drawn: a pervasive bipartisan presupposition of twentieth century ethical theory and deontic logic is false. Next, an intuitive model-theoretic framework for "must" and "ought" is hypothesized. It is then shown how this hypothesis helps to explain and (...) predict all the pre-theoretic phenomena previously observed. Next, I show that the framework hypothesized possesses additional expressive and explanatory power (e.g. derivatively predicting the existence of supererogatory and permissibly suboptimal alternatives), thus adding further confirmation that it is on the right track. (shrink)

De Finetti would claim that we can make sense of a draw in which each positive integer has equal probability of winning. This requires a uniform probability distribution over the natural numbers, violating countable additivity. Countable additivity thus appears not to be a fundamental constraint on subjective probability. It does, however, seem mandated by Dutch Book arguments similar to those that support the other axioms of the probability calculus as compulsory for subjective interpretations. These two lines of reasoning can be (...) reconciled through a slight generalization of the Dutch Book framework. Countable additivity may indeed be abandoned for de Finetti's lottery, but this poses no serious threat to its adoption in most applications of subjective probability. Introduction The de Finetti lottery Two objections to equiprobability 3.1 The ‘No random mechanism’ argument 3.2 The Dutch Book argument Equiprobability and relative betting quotients The re-labelling paradox 5.1 The paradox 5.2 Resolution: from symmetry to relative probability Beyond the de Finetti lottery. (shrink)

How can we think about things in the outside world? There is still no widely accepted theory of how mental representations get their meaning. In light of pioneering research, Nicholas Shea develops a naturalistic account of the nature of mental representation with a firm focus on the subpersonal representations that pervade the cognitive sciences.

This book presents new research into key areas of the work of German philosopher and mathematician Gottfried Wilhelm Leibniz (1646-1716). Reflecting various aspects of Leibniz's thought, this book offers a collection of original research arranged into four separate themes: Science, Metaphysics, Epistemology, and Religion and Theology. With in-depth articles by experts such as Maria Rosa Antognazza, Nicholas Jolley, Agustín Echavarría, Richard Arthur and Paul Lodge, this book is an invaluable resource not only for readers just beginning to discover (...) Leibniz, but also for scholars long familiar with his philosophy and eager to gain new perspectives on his work. (shrink)

The ‘convergence conception’ of political liberalism has become increasingly popular in recent years. Steven Wall has shown that convergence liberals face a serious dilemma in responding to disagreement about whether laws are publicly justified. What I call the ‘conjunctive approach’ to such disagreement threatens anarchism, while the ‘non-conjunctive’ approach appears to render convergence liberalism internally inconsistent. This paper defends the non-conjunctive approach, which holds that the correct view of public justification should be followed even if some citizens do not consider (...) enacted laws to be publicly justified. My argument sheds light on the fundamental structure of convergence liberalism. (shrink)

Commentators such as Terence Irwin (1999) and Christopher Shields (2006) claim that the Ring of Gyges argument in Republic II cannot demonstrate that justice is chosen only for its consequences. This is because valuing justice for its own sake is compatible with judging its value to be overridable. Through examination of the rational commitments involved in valuing normative ideals such as justice, we aim to show that this analysis is mistaken. If Glaucon is right that everyone would endorse Gyges’ behavior, (...) it follows that nobody values justice intrinsically. Hence, the Gyges story constitutes a more serious challenge than critics maintain. (shrink)

What is fanaticism and why is it an important philosophical topic? In this introductory chapter, I discuss the way in which fanaticism arose as a central philosophical concern in the early modern period. Philosophical discussions of fanaticism focus on psychological, epistemic, and behavioral dimensions of fanatics. The fanatic displays psychological peculiarities; epistemic defects; and potentially problematic behavioral tendencies. I discuss the ways in which different philosophers have offered different accounts of these three features; offer a brief defense of my own (...) account of fanaticism; and highlight some key questions about fanaticism. I close with an overview of the essays in this volume. (shrink)

Some environmental ethicists and economists argue that attributing infinite value to the environment is a good way to represent an absolute obligation to protect it. Others argue against modelling the value of the environment in this way: the assignment of infinite value leads to immense technical and philosophical difficulties that undermine the environmentalist project. First, there is a problem of discrimination: saving a large region of habitat is better than saving a small region; yet if both outcomes have infinite value, (...) then decision theory prescribes indifference. Second, there is a problem of swamping probabilities: an act with a small but positive probability of saving an endangered species appears to be on par with an act that has a high probability of achieving this outcome, since both have infinite expected value. Our paper shows that a relative concept of infinite value can be meaningfully defined, and provides a good model for securing the priority of the natural environment while avoiding the failures noted by sceptics about infinite value. Our claim is not that the relative infinity utility model gets every detail correct, but rather that it provides a rigorous philosophical framework for thinking about decisions affecting the environment. (shrink)

I explore various ways of integrating the framework for predeterminism, agency, and ability in[P.McNamara, Nordic J. Philos. Logic 5 (2)(2000) 135] with a framework for obligations. However,the agential obligation operator explored here is defined in terms of a non-agential yet personal obligation operator and a non-deontic (and non-normal) agency operator. This is contrary to the main current trend, which assumes statements of personal obligation always take agential complements. Instead, I take the basic form to be an agent’s being obligated to (...) be such that p. I sketch some logics for agential obligation based on personal obligation and agency, first in a fairly familiar context that rules out conflicting personal obligations (and derivatively, conflicting agential obligations), and then in contexts that do allow for conflicts (of both sorts). (shrink)

Iris Murdoch claims that “clear vision is a result of moral imagination and moral effort.” Our experience of the world can be blurred by egoism, inattentiveness, and other failings. I ask how we distinguish clear vision from distorted vision. Murdoch’s texts appeal to four factors: (A) attention; (B) unselfing; (C) a form of conceptual articulacy; and (D) love. I ask three questions about these standards: - Are these standards directed at the same goal? (For example, are they all geared toward (...) securing purely epistemic goals?) - Are these standards criterial for improvements in vision? (That is, does the presence of some combination of (A)-(D) constitute or guarantee better vision?) - Does Murdoch think that there’s a single best form of vision? (Such as the one attained by the person who manifests (A)-(D)?) In the secondary literature, the typical answers to these questions are: yes, yes, yes. But I give different answers: no, no, no. (shrink)

This Handbook contains forty essays by an international team of experts on the antecedents, the content, and the reception of the Dionysian corpus, a body of writings falsely ascribed to Dionysius the Areopagite, a convert of St Paul, but actually written about 500 AD. The first section contains discussions of the genesis of the corpus, its Christian antecedents, and its Neoplatonic influences. In the second section, studies on the Syriac reception, the relation of the Syriac to the original Greek, (...) and the editing of the Greek by John of Scythopolis are followed by contributions on the use of the corpus in such Byzantine authors as Maximus the Confessor, John of Damascus, Theodore the Studite, Niketas Stethatos, Gregory Palamas, and Gemistus Pletho. In the third section attention turns to the Western tradition, represented first by the translators John Scotus Eriugena, John Sarracenus, and Robert Grosseteste and then by such readers as the Victorines, the early Franciscans, Albert the Great, Aquinas, Bonaventure, Dante, the English mystics, Nicholas of Cusa, and Marsilio Ficino. The contributors to the final section survey the effect on Western readers of Lorenzo Valla's proof of the inauthenticity of the corpus and the subsequent exposure of its dependence on Proclus by Koch and Stiglmayr. The authors studied in this section include Erasmus, Luther and his followers, Vladimir Lossky, Hans Urs von Balthasar, and Jacques Derrida, as well as modern thinkers of the Greek Church. Essays on Dionysius as a mystic and a political theologian conclude the volume. (shrink)

Revealed that Bertrand Russell's Wisdom of the West was most likely actually written by its "editor", Paul Foulkes, in view of the prominence in the text of the ideas of Foulkes' teacher, John Anderson. That suspicion later turned out to be true.

In his last works, John Rawls explicitly argued for an overlapping consensus on a family of reasonable liberal political conceptions of justice, rather than just one. This ‘Deep Version’ of political liberalism opens up new questions about the relationship between citizens’ political conceptions, from which they must draw and offer public reasons in their political advocacy, and their comprehensive doctrines. These questions centre on whether a reasonable citizen’s choice of political conception can be influenced by her comprehensive doctrine. In this (...) paper I present two models of the relationship, which give contrasting answers to these questions, and defend the model that is more permissive with regard to the influence of comprehensive doctrines. This has important implications for our understanding of Rawlsian political liberalism, and reduces the force of objections that have been offered by theorists sympathetic to religion. (shrink)

In this article, I will discuss some of the arguments for and against the existence of God, in particular the monotheistic God believed in the Abramahamic religions (Judiasm, Islam, and Christianity) as well as Babism, the Bahai Faith, and Sikhism. Arguments for the existence of God try to argue that either God exists (based on other things people agree with) or that belief in God is reasonable. Arguments against the existence of God try to argue that the existence of God (...) leads to some contradiction or other absurdity. (shrink)