Abstract
It might seem inappropriate to describe Kant as an empiricist. He believed, contrary to the basic empiricist principle, that there are nontrivial propositions that can be known independently of experience. He devoted virtually all of his efforts as a researcher to discovering how it is possible for us to have this "synthetic a priori" knowledge. However, Kant also believed that there are some things that we can know only through sensory experience. Though he did not give these empirical propositions the attention he lavished on their a priori companions, they are both numerous and significant. The purpose of this article is to examine the role of empirical elements in Kant's thought, and to expand on some of the implications that a due appreciation of this empiricism has for the interpretation of his positions on causality, the systematic unity of laws, and realism. In the process a pair of hitherto neglected Kantian notions will come up for close scrutiny: those of affinity and of the exponent of a rule.