Known for distinguished work in the fields of metaphysics and philosophy of religion, Alvin Plantinga ventures further into epistemology in this book and its companion volume, _Warrant and Proper Function_. Plantinga examines the nature of epistemic warrant; whatever it is that when added to true belief yields knowledge. This present volume surveys current contributions to the debate and paves the way for his own positive proposal in _Warrant and Proper Function_. This first volume serves as a good introduction to the central issues in contemporary epistemology.