Traditional epistemology has been concerned with "justification". According to the traditional model of knowledge, some proposition p is knowledge if and only if:
some agent X believes p,
p is true,
X is justified in believing in p
Since the time of Descartes, who sought to establish the criteria by which true beliefs could be acquired, and to determine those beliefs we are in fact justified in believing, the primary epistemological project has been the elucidation of the justificatory condition in this conception of knowledge (i.e. justified true belief).
Naturalized epistemology had its beginnings in the twentieth century with W. V. Quine. Quine's proposal, which is commonly called "Replacement Naturalism," is to excise every trace of normativity from the epistemological body. Quine wanted to merge epistemology with empirical psychology such that every epistemological statement would be replaced by a psychological statement.
Epistemology is the study, or theory of knowledge, including the questions: What is knowledge? How is or should it be acquired, tested, stored, revised, updated, and retrieved?
Some goals of meta-epistemology are to identify inaccurate traditional assumptions, or hitherto overlooked scope for generalization. Thus whereas epistemology has usually been seen as a branch of philosophy, it may also take examples from biology which seem equivalent in relevant ways. Also, insofar as philosophy is involved, there may be a case for extending it beyond its traditional domain of word-based definitions.
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