Professor Plantinga is known for distinguished work in the fields of epistemology and philosophy of religion. In this companion volume to Warrant: The Current Debate, Plantinga develops an original approach to the question of what justifies belief and makes it knowledge. He argues that what is crucial to turning true belief into knowledge is the "proper functioning" of one's cognitive faculties, and this clears the way for the proposal that a belief is warranted whenever it is the product of properly functioning cognitive processes. Although this is in some sense a sequel to the companion volume, the arguments in no way presuppose those of the first book and it can therefore stand alone.

Here I must acknowledge a complication with respect to my way of thinking of warrant. I aim at something in the neighborhood of an analysis of warrant: an account or exploration of our concept of warrant, a concept nearly all of us have and regularly employ.

'Alvin Plantinga makes important contributions to a tradition of discussion which has dominated recent epistemology. Warrant: the Current Debate provides a critical survey of the most recent controbutions to American epistemology ... Plantinga discerns a pattern in their failure, and this is exploited in the second volume where he develops an original and important contribution of his own. Warrant and Proper Function undertakes to succeed where Roderick Chisholm, John Pollock, Louis BonJour, Alvin Goldman and others have failed ... Plantinga's books will provide a focus for much future research in these areas, as well as providing invaluable reading for students taking courses in epistemology.' Christopher Hookway, University of Birmingham, The Philosophical Quarterly, 1995