Philosophers now treat the relationship between Classical Mendelian Genetics and molecular biology as a paradigm of nonreduction and this example is playing an increasingly prominent role in debates about the reducibility of theories ranging from macrosocial science to folk psychology. Patricia Churchland (1986), for example, draws an analogy between the alleged elimination of the “causal mainstay” of classical genetics and her view that today’s psychological theory will be eliminated by neuroscience. Patricia Kitcher takes an autonomous rather than eliminativist view of (...) the reported nonreduction in genetics and reasons that psychology will retain a similar autonomy from lower level sciences (1980 and 1982). Although Churchland and Kitcher offer different interpretations of the apparent failure of molecular biology to reduce classical genetics, they agree that this failure will help illuminate theoretical relations between psychology and lower level sciences. The appearance of the Mendelian example along side the usual ones from physics and chemistry marks a turning point in philosophy of science. (shrink)