This volume presents three sets of papers discussing the medieval problem of singular cognition, nominalist epistemology, and the metaphysics of the great medieval nominalist philosopher, John Buridan. The first group of essays concerns issues surrounding the possibility of singular cognition in light of the cognitive psychology of Thomas Aquinas and Duns Scotus, as well as the latter’s argument from indifference as developed by William Ockham to support his own, nominalist epistemology. However, Ockham’s epistemology, worked out in detail by John Buridan, seems to have implications concerning the possibility of Demon Skepticism (later popularized by Descartes), which in turn poses a threat to the consistency of the nominalist cognitive psychology in general, as discussed in the second group of essays. Finally, the third group of essays explores some intriguing, but weird implications of the nominalist approach to epistemology in the metaphysics of John Buridan.