The concept of causation is essential to ascribing moral and legal responsibility since the only way an agent can make a difference in the world is through her acts causing things to happen. Yet the extent and manner in which the complex features of causation bear on responsibility ascriptions remain unclear. I present an analysis of four aspects of causation which yields new insights into different properties of responsibility and offers increased plausibility to certain moral views. Chapter I examines the realist assumption that causation is an objective and mind-independent relation between space-time located relata – a postulate meant to provide moral assessment with a naturalistic basis and make moral properties continuous with a scientific view of the world. I argue that such a realist stance is problematic, and by extension so are the views seeking to tie responsibility attributions to an objective relation. Chapter II combines the context sensitivity of causal claims with the plausible idea that responsibility ascriptions rest on the assessment of causal sequences relating agents and consequences. I argue that taking context sensitivity seriously compels us to face a choice between moral contrastivism and a mild version of scepticism, viz. responsibility is not impossible, but ultimately difficult to identify with confidence. I show why the latter view is preferable. Chapter III explores the concern that group agents would causally (and morally) overdetermine the effects already caused by their constituent individuals. I argue that non-reductive views of agency and responsibility lack a coherent causal story about how group agents impact the world as relatively independent entities. I explain the practical importance of higher-order entities and suggest a fictionalist stance towards group agency talk. Chapter IV analyses the puzzle of effect selection – if causes have infinitely many effects, but only one or a few are mentioned in causal claims, what determines their selection from the complete set of consequents? I argue that the criteria governing the difference between effects and by-products lack clarity and stability. I use the concerns about appropriate effect selection to formulate an epistemic argument against consequentialism.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The overall objective of this study is to undertake a critical evaluation of Joyce's proposal for a moral fictionalism. In order to meet this objective, the thesis is divided into two main parts, the first devoted to the reconstruction of Joyce's proposal and the second reserved, properly, their critical assessment. The theme of the first chapter is the theory of moral error, focusing primarily on the defense of the same taken by Joyce. The main objective that we have to address this issue is to indicate the problem to which Joyce solution proposes its moral fictionalism, which is the question of what to do with the moral discourse after the acceptance of the theory of moral error. The second chapter is devoted specifically to the reconstruction of Joyce's proposal for a moral fictionalism. The third chapter is a summary of the main criticisms of Joyce fictionalism. In the fourth chapter, finally, it is carried critical evaluation which is the objective of this thesis. The conclusion that is reached with such assessment, which is the argument of this thesis, is that the moral fictionalism proposed by Joyce does not seem to be able to meet two specific objectives for which it was proposed, namely, (1) retain a significant portion of the practical benefits of moral beliefs and (2) prevent the one who accepts the error theory can be accused of irrationality. With this, Joyce would not able to show that adherence to error theory would not have devastating consequences, not thus fulfilling the broader objective of its proposal for a moral fictionalism. Faced with this failure, the most appropriate attitude to the theoretical error that shares Joyce s concerns and objectives appears to be intended to support here, that position that the author calls "propagandism", which seems to be the most able to meet the objectives of its proposal. / O objetivo geral do presente estudo é proceder a uma avaliação crítica da proposta de Richard Joyce de um ficcionalismo moral. A fim de cumprir tal objetivo, o trabalho é dividido em duas partes principais, a primeira dedicada à reconstrução da proposta de Joyce e a segunda reservada, propriamente, à sua avaliação crítica. O tema do primeiro capítulo é a teoria do erro moral, focando-se, principalmente, na defesa da mesma empreendida por Joyce. O principal objetivo que se tem ao tratar desse tema é indicar o problema para cuja solução Joyce propõe seu ficcionalismo moral, o qual consiste na questão sobre o que fazer com o discurso moral após a aceitação da teoria do erro moral. O segundo capítulo é dedicado, especificamente, à reconstrução da proposta de Joyce de um ficcionalismo moral. No terceiro capítulo, é apresentado um resumo das principais críticas ao ficcionalismo de Joyce. No quarto capítulo, por fim, é procedida a avaliação crítica que constitui o objetivo deste estudo. A conclusão a que se chega com tal avaliação, que constitui a tese defendida neste trabalho, é que o ficcionalismo moral proposto por Joyce parece não ser capaz de cumprir os dois objetivos específicos para os quais ele foi proposto, a saber, (1) conservar uma porção significativa dos benefícios práticos das crenças morais e (2) evitar que aquele que aceita a teoria do erro possa ser acusado de irracionalidade. Com isso, Joyce acabaria não conseguindo mostrar que a adesão à teoria do erro não precisaria ter consequências devastadoras, não cumprindo, assim, o objetivo mais geral subjacente à sua proposta de um ficcionalismo moral. Diante de tal fracasso, a atitude mais adequada para o teórico do erro que partilha as preocupações e objetivos de Joyce parece ser, pretende-se sustentar aqui, aquele posicionamento que o autor chama de propagandismo , o qual parece ser o mais apto a cumprir os objetivos de sua proposta.

Les fictions posent problème en philosophie, que l'on soit porté sur les considérations ontologiques, épistémologiques, logiques ou esthétiques. Dans un livre important nommé Mimesis as Make-Believe (1990), Kendall Walton proposa une théorie de la représentation qui révolutionna notre compréhension des fictions. En résumé, elle met en avant la notion de fictionalité, ou vérité dans la fiction, qu'elle définit en termes de prescription imaginative. La présente étude porte sur la philosophie de Walton, sur la théorie de Mimesis, sur les critiques qu'elles ont reçues. La première partie est une présentation de la méthodologie philosophique de Walton et d'un de ses articles les plus influents, "Categories of Art" (1970). La seconde partie est un commentaire détaillé de Mimesis, construit sur une opposition entre la théorie de la représentation de Nelson Goodman (1968) et celle de notre philosophe. La troisième partie concerne les critiques reçues par la théorie. Une partie d'entre elles proviennent de philosophes qui admettent les principes fondamentaux de sa théorie : ce sont les critiques intentionnalistes de Gregory Currie (1990), Peter Lamarque et Stein Olsen (1994), ou encore Jerrold Levinson (1993). Je défends que ces critiques sont inopérantes. Une autre partie d'entre elles proviennent de philosophes qui cherchent à miner ces principes fondamentaux : ce sont les critiques de Stacie Friend (2008), Derek Matravers (2014), voire de Walton (2015) lui-même. Je défends que, bien comprises, ces critiques ne sont pas décisives, mais qu'elles sont importantes. Elles devraient nous orienter vers une meilleure compréhension des aspects sémiotiques de la fictionalité. / The ordinary concept of fiction raises ontological, epistemological, logical and aesthetical questions. Kendall Walton's Mimesis as Make-Believe (1990) introduced a groundbreaking theory on fiction and representation. According to his main claim, the practice of appreciating representational works of art shares significant similarities with the practice of playing games of make-believe. According to Walton, both activities rely on the concept of fictionality, the fact of being true in the fiction, which is understood in terms of prescriptions to imagine. My dissertation consists of an introduction to Walton's philosophy, a commentary of Mimesis' theory of make-believe and a defense against their critics. The first part provides a presentation of Walton's philosophical methodology and discusses one of his most famous articles, "Categories of Art" (1970). The second part provides a detailled commentary of Mimesis, based on a confrontation between Nelson Goodman's theory of representation and Walton's one. The third part is dedicated to analyse the criticisms that are encountered by the theory. A first set of criticisms comes from philosophers admitting the fundamental principles of the theory : those are Gregory Currie (1990), Peter Lamarque and Stein Olsen (1994), or Jerrold Levinson (1993). I argue that those objections are groundless. Another set of criticisms comes from philosophers attempting to undermine the fundamental principles of the theory : those are Stacie Friend (2008), Derek Matravers (2014), or even Walton himself (2015). According to me, those objections are on the right tracks if correctly understood, but fall short from being decisive. Nevertheless, I argue they should lead us to develop a research on the semiotic aspects of fictionality.

This dissertation is centered around a set of apparently conflicting intuitions that we may have about mathematics. On the one hand, we are inclined to believe that the theorems of mathematics are true. Since many of these theorems are existence assertions, it seems that if we accept them as true, we also commit ourselves to the existence of mathematical objects. On the other hand, mathematical objects are usually thought of as abstract objects that are non-spatiotemporal and causally inert. This makes it difficult to understand how we can have knowledge of them and how they can have any relevance for our mathematical theories. I begin by characterizing a realist position in the philosophy of mathematics and discussing two of the most influential arguments for that kind of view. Next, after highlighting some of the difficulties that realism faces, I look at a few alternative approaches that attempt to account for our mathematical practice without making the assumption that there exist abstract mathematical entities. More specifically, I examine the fictionalist views developed by Hartry Field, Mark Balaguer, and Stephen Yablo, respectively. A common feature of these views is that they accept that mathematics interpreted at face value is committed to the existence of abstract objects. In order to avoid this commitment, they claim that mathematics, when taken at face value, is false. I argue that the fictionalist idea of mathematics as consisting of falsehoods is counter-intuitive and that we should aim for an account that can accommodate both the intuition that mathematics is true and the intuition that the causal inertness of abstract mathematical objects makes them irrelevant to mathematical practice and mathematical knowledge. The solution that I propose is based on Rudolf Carnap's distinction between an internal and an external perspective on existence. I argue that the most reasonable interpretation of the notions of mathematical truth and existence is that they are internal to mathematics and, hence, that mathematical truth cannot be used to draw the conclusion that mathematical objects exist in an external/ontological sense.

The normative political theory problem of dirty hands (DH) concerns the troubling possibility that political leaders, from a (mostly) consequentialist perspective, might sometimes be morally required to make exceptions from sensitive rules like prohibitions of extremely harmful practices (e.g. torture) in order to avert catastrophic threats and crises, while such rules are still considered so important and such crises so rare that one nonetheless feels inclined to deem dirty exceptions categorically wrong so as to prevent their unnecessary proliferation through a slippery-slope type development.  How can we conceptualize such a problematic necessity? A latent but insufficiently explored idea in the DH literature is that the normatively preferrable approach to such a wicked problem might be to not try to conceptualize it at all, or at least not in our public work as academics. In this thesis, I introduce the straightforward suggestion that if the DH problem cannot be discussed without risking slippery-slope demoralization of the partaking deliberators and/or audience, we seem to be morally required to content ourselves with terming it an unspeakable, taboo subject in non-crisis times, as a meta-level ersatz solution to the core-level political problem conventionally centered in the DH literature.  I also discuss to what extent the mainstream, weak rule utilitarian (WRU) DH literature can themselves be understood as intentionally testing the limits of consequentialist reasoning in a search for a 'higher' moral truth than what their ethical position might entail at first glance.