Abstract

In this essay I discuss the evolution of A. J. Ayer’s account of the mind-body relation through his career, with an emphasis on his early ideas. The reconstruction of Ayer’s ideas on this particular topic, beyond being interesting in itself, may also be illuminating inasmuch as it provides further details on the path Ayer carved out for himself within the large-scale development of analytic philosophy, progressing from the radical anti-metaphysicalism of the logical positivists in the 1930s towards the (re)birth of analytic metaphysics in the 1960s. Ayer’s philosophical development may be divided into two major periods characterized by a comprehensive phenomenalist and a “sophisticated realist” approach. In the phenomenalist period, Ayer regarded the question of whether sense-data are mental or physical nonsensical, and he did not address the nature of the psychophysical relation either. After the realist turn, however, he did find these questions meaningful, and discussed them in detail. In LTL and other prominent works from the phenomenalist period, issues concerning the nature of mind, body and their relation were expounded primarily through linguistic analysis, i.e. by investigating the meaning of sentences reporting mental states of one’s own and of others as well as of perceptual reports. These investigations were framed by Ayer’s views on the privacy or publicity of sense-data and phenomenalistic language, which changed significantly several times. In laying out Ayer’s phenomenalism I also discuss his views on privacy in some detail. Furthermore, I briefly touch upon Ayer’s account of the psychophysical relation in the late realist period, which may be characterized by his trenchant “anti-physicalism”, and his wavering between a mere correlation view and a version of Russellian monism. These later views were laid out in the “sophisticated realist” framework and may be considered metaphysical, in contrast with Ayer’s earlier purely linguistic approach.