During the past two or three decades, justification has become a central topic in epistemology. The interest in justification grew out of the attempts to give the correct analysis of knowledge in the face of the famous counterexamples given by Edmund Gettier to the so-called traditional conception of knowledge in his 1963 paper. The interest in knowledge may have decreased, but the disputes about the right account of justification go on more vigorously than ever. Indeed, there are at present so many distinct theories of epistemic justification advocated by different disputants that it makes one doubt whether they are actually talking about the same thing at all. Before considering these theories, we shall therefore make first an attempt to locate the common concept or property that they are all theories of.