My thesis tackles two related problems that have taken center stage in the recent literature on concepts: • What are the individuation conditions of concepts? Under what conditions is a concept C₁ the same concept as a concept C₂? • What are the possession conditions of concepts? What conditions must be satisfied for a thinker to have a concept C? I will develop a pluralist and contextualist theory of concept individuation and possession: different concepts have different individuation and possession conditions, and contextual factors play a crucial role in determining what concepts we attribute to other subjects when we ascribe propositional attitudes to them. In chapters 1-3, I defend a contextualist, non-Millian theory of propositional attitude ascriptions. Then, I suggest contextualist theories of ascriptions can be applied to the problem of concept individuation/possession. In particular, I use contextualism to provide a new, more effective argument for Fodor's “publicity principle”, according to which concepts must be shared in order for interpersonally applicable psychological generalizations to be possible. Publicity has important implications: in particular, it is inconsistent with existing versions of holism, on which concepts cannot be shared by ordinary thinkers. Nonetheless, in chapters 4-5 I show how holism can still play an important role in our best theory of concepts. More specifically, I argue that the tradition of appealing to modes of presentation in order to give an account of “Frege cases” is in fact committed to holism. To develop a version of holism that will give a successful account of Frege cases without violating publicity, I suggest we should adopt my pluralist-contextualist picture: on that picture, the concepts involved in a Frege case will be holistically individuated and not public, while other concepts will be more coarsely individuated and widely shared. In chapter 6, I will develop this view further by contrasting it with other pluralist theories (Weiskopf) and with rival theories of concepts, such as the localist views defended by Peacocke, Rey and Jackson.

Dans cette thèse je défends l'élimination des concepts d'attitudes propositionnelles. Dans le premier chapitre, je présente les thèses éliminativistes en philosophie de l'esprit et des sciences cognitives contemporaines. Il y a deux types d'éliminativisme: le matérialisme éliminatif et l'éliminativisme des concepts. Il est possible d'éliminer les concepts soit des théories naïves soit des théories scientifiques. L'éliminativisme à propos des concepts d'attitudes propositionnelles que je défends requière le second type d'élimination. Dans les trois chapitres suivants je donne trois arguments en faveur de cette thèse. Je commence par soutenir que la théorie interventionniste de la causalité ne fonde pas nos jugements de causalité mentale. Ensuite je montre que nos concepts d'attitudes propositionnelles ne sont pas des concepts d'espèces naturelles car ils groupent ensemble les états des différents modules d'une architecture massivement modulaire, la thèse de modularité massive faisant partie, je l'affirme, de notre meilleur programme de recherche. Finalement, mon troisième argument repose sur l’élimination du concept de contenu mental de nos théories. Dans les deux derniers chapitres de la thèse, je défends ce dernier argument. Tout d'abord, je réfute l'argument du succès selon lequel étant donné que les psychologues emploient le concept de contenu mental et ce faisant produisent de la bonne science ce concept ne devrait pas être éliminé. Ensuite je rejette une autre façon d'éliminer ce concept, celle choisie par les théoriciens de la cognition étendue. Pour cela je réfute le meilleur argument qui a été donné en faveur de cette thèse: l'argument du système. / In this dissertation, I argue for the elimination of propositional attitudes concepts. In the first chapter I sketch the landscape of eliminativism in contemporary philosophy of mind and cognitive science. There are two kinds of eliminativism: eliminative materialism and concept eliminativism. One can further distinguish between folk and science eliminativism about concepts: whereas the former says that the concept should be eliminated from our folk theories, the latter says that the concept should be eliminated form our scientific theories. The eliminativism about propositional attitudes concepts I defend is a species of the latter. In the next three chapters I put forward three arguments for this thesis. I first argue that the interventionist theory of causation cannot lend credit to our claims of mental causation. I then support the thesis by showing that propositional attitudes concepts aren't natural kind concepts because they cross-cut the states of the modules posited by the thesis of massive modularity, a thesis which, I contend, is part of our best research-program. Finally, my third argument rests on science eliminativism about the concept of mental content. In the two last chapters of the dissertation I first defend the elimination of the concept of mental content from the success argument, according to which as psychologists produce successful science while using the concept of mental content, the concept should be conserved. Then, I dismiss an alternative way of eliminating the concept, that is, the way taken by proponents of extended cognition, by refuting what I take to be the best argument for extended cognition, namely, the system argument.