Weismann, Wittgenstein and the homunculus fallacy

A problem that has troubled both neo-Darwinists and neo-Lamarckians is whether instincts involve knowledge. This paper discusses the contributions to this problem of the evolutionary biologist August Weismann and the philosopher Ludwig Wittgenstein. Weismann discussed an empirical homunculus fallacy: Lamarck’s theory mistakenly presupposes a homunculus in the germ cells. Wittgenstein discussed a conceptual homunculus fallacy which applies to Lamarck’s theory: it is mistaken to suppose that knowledge is stored in the brain or DNA. The upshot of these two fallacies is that instincts arise through a neo-Darwinian process but are not cognitions in the sense that they involve (the recollection of stored) knowledge. Although neo-Lamarckians have rightly argued that learning processes may contribute to the development of instincts, their ideas about the role of knowledge in the evolution and development of instincts are mistaken.