Deborah Cook at the TLS:
The lectures reveal the various themes and preoccupations in Foucault’s work in the 1970s and 80s; they also help to contextualize many of the changes in his thought. Still, it is difficult to characterize Foucault’s work. He often denied that he was a theorist, by which he meant someone who works within an overarching system. Describing himself as an experimenter, Foucault frequently underscored the tentative and fragmentary nature of his research. His work is also anti-systematic in the sense that it explores the logic of specific mechanisms, technologies and strategies of power. This exploration requires that close attention be paid to historical conditions whose singularity defies subsumption under a universal history. But Foucault’s antipathy towards systematic thought also meant that he enthusiastically pursued new directions in his research (his later study of care of the self in ancient Greece and Hellenistic Rome is a case in point), and he readily acknowledged the disparities between his earlier and later work.
more here.