His book rested on constricted historical documentation, yet this have vibrated good idea because he explained what’s going on in his cultural analysis. Many of us who have learned from Foucault read him because of the way he looks at his sources. He invites us to reverse some of the historical causality more than did by other historians. He was concerning with "becoming what one was," and folie et déraison was his first attempt to become himself.
Rising above the Cartesian Weltanschauung, he show us what lies beyond its arbitrary structures, he reverses the paradigm, making a mockery of asylum in that Madness book. He discards the arbitrary constraints of reason, reexamines and reconnects aspects of language said to have been irreconcilable. He also attempts to reveal the ultimate philosophical irony: truth often lies not so much in scientific method, with its birth perhaps in the Socratic method, but in discourse, in an analysis of established categories of language, thought, and history.
However hard his book is in my own capacity, however unconventional his way of life, he evidently helps readers understand how they live now and here. It’s good thing, I think.