Abstract

Individualism is the view that psychological kinds must be defined only in terms of the internal properties of individual subjects. The argument for this view is that anything external to the individual cannot have any causal explanatory relevance to that individual's behavior. This assumes that to be scientific, psychology must individuate mental states by causally relevant properties. But I argue first, that this rules out individuating them by any sort of representational content. Second, if taken seriously, it entails that only kinds in the physical sciences are scientific. Thus we must either reject individualism or acknowledge that psychology is not a science. ;I find the first option more reasonable, so I develop a non-individualistic way of understanding psychology, founded in evolutionary biology. Anatomical, physiological and ethological kinds are individuated by functions , and, because of these functions, two sorts of biological explanation are possible. On the one hand, to attribute a function to something is to provide it with an historical explanation. On the other, we can explain certain events in terms of items that have the function of producing them. Thinking about the functions of mental states clarifies the nature of representational content. It also shows how psychological explanations, in citing beliefs and desires individuated by their contents, simultaneously tell us a behavior's function, as well as telling us what states, functionally individuated, caused the behavior. Thus it combines the two forms of biological explanation mentioned above. If this biological model of psychology is true, we can retain some of our common sense conception of the mind, while also thinking about the mind scientifically