Abstract

This dissertation is a study of the dualistic implications of a doctrine which is as old as the corpuscular hypothesis of early seventeenth century science and as current as particle physics: the doctrine of primary and secondary qualities . PSQD states that some of the most familiar qualities of the macroscopic world, namely color, brightness, sound, odor, flavor, heat and cold, must not be regarded as intrinsic properties of material things but instead as sensations in the minds of percipient organisms. ;I examine the two physics-theoretical arguments on which PSQD stands, arguments set out by Descartes in the Principles of Philosophy, and again, in our time, by Wilfrid Sellars. The most basic of these arguments shows that theoretical explanations of secondary qualities are ultimately unintelligible. The second argument shows that secondary qualities can play no role in the explanation of the behaviors of physical things. ;The thesis of this dissertation is that PSQD, as supported by the theoretical arguments, imposes severe constraints on theories of the relation of mind and body. It does so because the theoretical arguments apply straight-forwardly to neurological objects and processes. In this context, the theoretical arguments are arguments for mind-body dualism. ;I develop this thesis in reference to the material theories of mind of four contemporary philosophers who subscribe to PSQD, namely H. Feigl, W. Sellars, J. J. C. Smart and D. Dennett. These four theories together represent the gamut of possibilities for a material theory of mind, with respect to their treatments of sensations of secondary qualities. ;I argue that the theories of the former two philosophers are radically inconsistent with the argumentative commitments incurred by PSQD. The theories of Smart and Dennett are, at least in conception, not inconsistent, but they are vague insofar as they attempt to eliminate the secondary properties from minds as well as from physical things. ;Finally, I propose arguments that Smart's theory is in fact ultimately inconsistent, and that Dennett's theory escapes inconsistency only at the cost of incoherency. If these arguments are sound they show that PSQD leads inevitably to mind-body dualism