The traditional philosophical category of epistemology serves medieval philosophy poorly. The medievals were concerned with most of what now falls within the theory of knowledge, but they never thought of knowledge as the sort of integrated topic around which one might construct a philosophical theory. Much the same might be said about philosophy today. In place of knowledge, philosophers now focus their energies on cognition; in place of the theory of knowledge, we now have cognitive theory. This way of dividing up the philosophical terrain turns out to be well suited to the study of medieval philosophy. The medievals, rather than focusing on how knowledge differs from mere true belief, focus on how we manage to form true beliefs: How does the process work? To answer this question is to develop a theory of cognition.

As in most matters, John Duns Scotus does not distinguish himself in cognitive theory by adopting a radically new perspective. Scotus accepts the general cognitive framework set out by his most distinguished recent predecessors, Thomas Aquinas and Henry of Ghent; where he disagrees, he does so in ways that reinforce the broader contours of the theory. Scotus is interesting, then, not because he offers any startlingly new ideas about cognition, but because he gives a careful and penetrating analysis of the field as it stood at the end of the thirteenth century. In many ways, he sees the issues in more depth than had anyone before him.