ABSTRACT
The ‘a priori sciences’ to be considered here are logic and arithmetic; the ‘psychology’ includes experimental, especially developmental, psychology, neurophysiology, and vision science. My goal is to examine the role these empirical theories can play in the philosophies of those sciences, or, more precisely, the role I think they should play. Most of the psychological studies referred to here will be familiar to readers of this volume, though perhaps not the use to which I hope to put them.
