Alvin Plantinga, who earned his PhD at Yale, has held the University of Notre Dame’s John A O‘Brien Chair of Philosophy since 1982. He is also a founder, and past president of, the Society of Christian Philosophers.
Plantinga’s major contributions to philosophy include his work on modality, and his application of that work to the ontological argument for God’s existence.
He is perhaps best known, however, for his work on reformed epistemology; Plantinga contends that certain beliefs, including religious beliefs, can be rational even if not based on evidence (c.f. his “Theism, Atheism, and Rationality”).