Epistemology is that branch of philosophy which deals with the character of knowledge. It is the study of what constitutes knowledge, considering its construction, its limits and its validation. An epistemology is a theory of knowledge. Since Descartes in the 17th century much philosophy has in various ways centred on the problem of knowledge. It was not until the end of the 19th century with Neitzche, and then in the 20th century with Heidegger, that epistemology was dropped from its prime position in philosophy, though it is still remains there in positivism. The turn in Anglo-American archaeology in the 1960s to the question of what constitutes knowledge of the material past was (and still is) an interest in positivism. qv constructivist philosophy and sociology of science

A recent interest of British postprocessual social archaeology is in the importance to social reproduction of knowledge, practical and propositional or discursive (available to expression in discourse). An interest in technical knowledge and practice has a long standing in French archaeology. This concern with know-how, skills and technology seems very appropriate to a field of study centred upon material culture. The reference in social theory is to people as knowledgable agents, skilled in social practice and who monitor the consequences of practice.