Psychologism, Semantics and the Subject Matter of Logic

Abstract

<p>Despite a pronounced rejection of psychologism at the turn of the previous century, contemporary epistemology has witnessed its pervasive return. This inquiry seeks to contribute to a philosophical resolution of the psychologism de bate, not by defending antipsychologism against its historical and contemporary objectors, but by offering a perspective from which a viable anti-psychologism might be articulated. Psychologism about logic is a family of views asserting a dependency of logic on psychology. Typically, such a dependence jeopardizes the objectivity and necessity of logic. Frequently, this dependency is established through the metaphysical claim that the subject matter of logic is psychological in nature. Metaphysical accounts of logic explain its status and foundation in terms of its subject matter. Standard accounts have portrayed the subject matter of logic as a class of mental entities (ideas), abstract entities, or concrete, particular entities. Following a review of Frege's critique of psycho logism (the first option), I consider historical representatives of the two remaining alternatives: Frege's Platonism and Mill's empiricism. Witnessing the failings of each of these theories, I turn to a positivistic account which provides logic with a linguistic, rather than a metaphysical, foundation. As an alternative to metaphysical accounts, I consider the view that logic has no subject matter. I argue that metaphysical accounts of logic may be equivalently expressed as theses concerning the semantics of the logical lexicon. Specifically, the question of psychologism may be seen as the question of how to properly explain the semantics of the logical lexicon. I engage Quine's response to positivistic accounts of logic, arguing that his naturalised holism misconstrues logic's function in theory and its fuundation. I suggest that a pragmatic account of logic, focussing on the linguistic function of logical expressions in our language, may provide a viable alternative for explaining the nature and foundation of logic.</p>