Final Causes and Natural Classes

Abstract

Though Peirce’s theory of natural classes is often mentioned in contemporary philosophy of science and metaphysics (Ian Hacking for example gives Peirce a prominent place in the tradition of natural kinds1), it has not as yet been studied thoroughly. Accordingly, the presentation of Peirce's theory is often only partially correct, and sometimes even misleading. Perhaps the main reason for the absence of a thorough study is that Peirce's theory of natural classes is intimately related to his theory of final causation,2- a concept which in contemporary philosophy is avoided for being a mystifying idea which neither agrees with the methods nor with the results of modern science. In the previous chapter I have tried to show that this is a biased view, due to a number of false presuppositions that were clearly recognized by Peirce a century ago. In this chapter it will be shown that Peirce's theory of natural classes is intimately linked to his conception of final causation.