Abstract
Ruth Millikan and Mark Bickhard both offer theories of representation that can be understood as broadly teleosemantic. Both agree that representations have an essentially normative character and that their normativity should be understood by appealing to some biological notion of function. Their fundamental difference has to do with their accounts of biological function. Millikan offers an etiological account of function, according to which the function of a thing is to be understood in terms of what is has been designed to do, or been selected for. According to such an account, whether or not a thing has a particular function depends on the history of the thing. Bickhard, in contrast, argues that we should understand function in non-etiological terms. Instead of appealing to design or selection, Bickhard appeals to the notion of dynamic presuppositions. Living beings are complex systems that involve multiple interconnected processes and there are dynamic presuppositions between the various processes. So according to such an account the reason why the function of the heart is to pump blood, is not because it was selected for this task, but that if it stopped pumping blood the whole organism would die, including the heart itself. I will argue that both Bickhard and Millikan are substantially correct in their positive theses. Rather than being incompatible theories that are attempting to explain the same thing, they offer distinct notions of function, biological normativity and representation that both have their place and provide for distinct, but equally valid and non-competing types of explanation.