Archaeology of Knowledge Edit
Foucault's work here is anti-humanist, not interested in the subject as being a center of knowledge (anti-phenomenology). There is no meaning beneath the statement (no kernal of truth), no hermenuetic imperative, nor essence, nor transcedental subject. Rather, there are statements and discourse formations; he is interested in the conditions of the existence of meaning, not meaning per se.
From Stanford Philosophical Encyclopedia:
Archaeology was an essential method for Foucault because it supported a historiography that did not rest on the primacy of the consciousness of individual subjects; it allowed the historian of thought to operate at an unconscious level that displaced the primacy of the subject found in both phenomenology and in traditional historiography. However, archaeology's critical force was restricted to the comparison of the different discursive formations of different periods. Such comparisons could suggest the contingency of a given way of thinking by showing that previous ages had thought very differently (and, apparently, with as much effectiveness). But mere archaeological analysis could say nothing about the causes of the transition from one way of thinking to another and so had to ignore perhaps the most forceful case for the contingency of entrenched contemporary positions. Genealogy, the new method deployed in Discipline and Punish, was intended to remedy this deficiency.
Foucault intended the term “genealogy” to evoke Nietzsche's genealogy of morals, particularly with its suggestion of complex, mundane, inglorious origins — in no way part of any grand scheme of progressive history. The point of a genealogical analysis is to show that a given system of thought (itself uncovered in its essential structures by archaeology, which therefore remains part of Foucault's historiography) was the result of contingent turns of history, not the outcome of rationally inevitable trends.