Proper Function and the Conditions for Warrant: What Plantinga’s Notion of Warrant Shows about Different Kinds of Knowledge

Alvin Plantinga’s Warrant and Proper Function gives two major definitions of warrant. One states that reliable cognitive faculties aimed at true belief and functioning properly in the right environment are necessary and sufficient for warrant; the other definition only states that they are necessary. The latter definition is the more important one. There are different kinds of knowledge, and justification is necessary for some beliefs to be warranted. Even a belief warranted by proper function can receive a higher degree of warrant by justification. This implies that natural theology has a useful role within the contours of a Plantingian epistemology.