As the term "justification" is used in epistemology, a belief is justified if one has good reason for holding it. Loosely speaking, justification is the "reason" that someone holds a rationally admissible belief, on the assumption that it is a "good reason" for holding it. Sources of justification might include perceptual experience (the evidence of the senses), reason, and authoritative testimony, among others. Importantly however, a belief being justified does "not" guarantee that the belief is true, since a person could be justified in forming beliefs based on very convincing evidence that was nonetheless deceiving.