Abstract

Since functionalism implies that mental categories cross classify physical categories, it has classically been construed as precluding both the reduction of psychological theory to physical theory as well as the replacement of psychological by physical theory. However, many recent arguments for psychophysical reductionism and eliminative materialism also presuppose that mental categories cross classify physical categories. This raises questions as to the true significance of the cross classification of mental and physical categories. ;I argue that viewing psychophysical reductionism or eliminative materialism as compatible with the cross classification of mental and physical categories presupposes a flawed view of explanation. More specifically, it disregards the fact that explanation essentially involves an audience. One cannot judge that a certain quantity of information does in fact explain a given explanandum without taking into consideration certain features of the relevant audience such as its interests and cognitive ability. I present reasons for believing explanation to be cognitively constrained and interest-relative. Given such reasons, arguments for psychophysical reductionism and eliminative materialism lose their plausibility. I conclude that functionalist metaphysics does indeed preclude both eliminative materialism and psychophysical reductionism. ;While most of my discussion concerns the physical irreducibility of psychological theory, I dispute Jerry Fodor's claim that this irreducibility implies that psychology must remain an autonomous science. I attempt to show that, while functionalist psychology does have a certain prima facie plausibility, it is only likely to be confirmed by being explained in terms of some other field of science. I do so by appealing to Michael Friedman's argument to the effect that the unification of the sciences plays a crucial role in the confirmation of theories. Since a physical reductive explanation of psychology has been ruled out, this raises the question as to what field one should look to in explaining psychological theory. ;In the Appendix, I attempt to show the plausibility of seeking an explanation of functionalist psychology in terms of evolutionary biology. I show that while the cross classification of mental and physical categories foils a physical reduction of psychological theory, it does not rule out an adaptationist explanation of psychological features.