The Ontogeny of Quine’s Ontology

Quine’s philosophical views did not emerge fully formed in the 1930s; rather, they changed over the seven decades he was philosophically active. This chapter investigates two episodes in Quine’s ontological development: his engagement with Pythagoreanism (an Appendix with new primary sources is included), and his conversion from nominalism to Platonism about mathematics. These two topics might seem completely distinct. However, although they could conceivably be treated separately, this chapter treats them together by considering the role clarity plays in both these episodes. Quine’s changing views about the theoretical virtue of clarity, and which particular things are clear and which are not, help explain his ontological development. In particular, the chapter offers a new hypothesis about the causes of Quine’s conversion from nominalism to realism, in which his views about clarity play an essential role.