Meta-epistemology is a metaphilosophical study of the subject, matter, methods and aims of epistemology and of approaches to understanding and structuring our knowledge of knowledge itself. In epistemology, there are two basic meta-epistemological approaches: traditional "normative" epistemology, and naturalized epistemology. Traditional epistemology has been concerned with "justification". According to the traditional model of knowledge, some proposition p is knowledge if and only if: 1. * some agent X believes p, 2. * p is true, 3. * X is justified in believing in p