Christopher Peacocke's theory of concepts, as put forward in his A Study of Concepts (SOC), is possibly the most influential of the neo-Fregean accounts of mental content, which - roughly - regard concepts as the mental equivalents of Fregean senses. Neo-Fregean accounts aim to take advantage of the explanatory power of Frege's Sinn/Bedeutung distinction, while avoiding the epistemic entanglements involved in Frege's notion of "grasping the sense" of an expression.
In this paper, I would like to examine two possible problems posed by Peacocke's theory of concepts. In the first section of the paper, I will briefy expose Peacocke's theory of concepts in its standard form (i.e.as presented in SOC). Peacocke's version of neo-Fregeanism is a two-stage theory. In a first stage, concepts are identified - at least for theory-making purposes - with possession/individuation conditions: according to what Peacocke calls the Principle of Dependence. Giving an account of a particular concept amounts to no more than giving an account of what it is for a thinker to master that concept, of what conditions a thinker must meet in order to posses the concept in question. In the second stage, Peacocke adds what he calls the Determination Theory (DT), an extra constraint on the the Principle of Dependence which is meant ensure that concept possession and individuation are linked to reference.
In the second section of the paper, I will question Peacocke's motivation for linking concept possession/individuation to reference. For even though Peacocke claims that a DT is indispensable to any account of concepts, it appears to be possible to have a theory of concepts which accepts the first stage of the theory but not the second one. Peacocke's insistence on the necessity of a DT appears is linked to his dictum that "judgement aims at truth". This, I will argue, is a questionable dictum, for by "judgement" Peacocke seems to understand a double-barrelled inferential-referential process - where each of the halves of the process, the inferential and the referential, would correspond, respectively, to either stage of his theory of concepts. Indeed, Peacocke goes so far as to claim that to possess a concept is to know what it is for something to be its semantic value. If a concept cannot be assigned a reference - if it is not possible to describe a state of affairs such that it would constitute its semantic value - then it isn't a concept at all, but only a spurious concept. I will claim on the contrary that it might be possible to give a more restricted definition of judgement which did not involve necessarily linking inference to reference - that is, defining judgement exclusively in inferential terms.
Finally, in the third section of the paper, I will turn to more recent developments. For in his more recent work, (i.e. The Realm of Reason), Peacocke has been increasingly relying on the new notion of subpersonal, doxastic implicit conceptions in order to patch up the gaps in his previous account of concept possession. In this final section, I will discuss how grounding concept possession in implicit conceptions can undermine Peacocke's very project of a theory of concepts altogether.