Cognition is a basic introductory text for college courses in the philosophy of knowledge. Joseph Owens here expands the narrowly metaphysical treatment of knowledge given in his earlier book, An Elementary Christian Metaphysics into a fully-fledged epistemology. This text utilises the traditions of Aristotle and Thomas Aquinas to reacquaint students of philosophy with a number of insights which are basic to a philosophic understanding of knowledge. These insights into the nature of abstraction, truth, the ground of certitude, and other major concerns of epistemology are intended to help students clarify the approaches of contemporary philosophies.