Functionalism and structuralism as philosophical stances: van Fraassen meets the philosophy of biology

I consider the broad perspectives in biology known as 'functionalism' and 'structuralism', as well as a modern version of functionalism, 'adaptationism'. I do not take a position on which of these perspectives is preferable; my concern is with the prior question, how should they be understood? Adapting van Fraassen's argument for treating materialism as a stance, rather than a factual belief with propositional content, in the first part of the paper I offer an argument for construing functionalism and structuralism as stances also. The argument draws especially on Gould's (The structure of evolutionary theory. Harvard University Press, Cambridge, 2002) insights concerning functionalism and structuralism, in particular their apparent historical continuity from the pre-Darwinian period through to today. In the second part of the paper I consider Godfrey-Smith's distinction between empirical and explanatory adaptationism, and suggest that while the former is an empirical scientific hypothesis, the latter is closely related to the functionalist stance.