Michel Foucault had some truly brilliant and important insights about power, insights that have had an important influence on some of today’s most prominent activist movements, and that arguably should be having more of an influence on others. It’s true that there’s a lot to take issue with in his work—I’ll come to that in a moment—but as I see it, there’s also a lot to be inspired by.

First of all, Foucault rejects the standard picture according to which power is always about the strong oppressing the weak, the rich oppressing the poor, the monarchy oppressing its subjects. Instead he suggests that in the modern world, power is spread throughout society. You and I are just as much conduits of power as a CEO or a member of congress: we internalize the norms of our society, and we end up policing ourselves and other people, whether we realize it or not. We all act as unwitting enforcers of the power structure.

So it’s no longer a simple “us versus them” story. And one consequence is that we can start thinking of injustice as something systemic or structural: injustice is not just a set of acts that bad people do, but a system that even otherwise good people can end up perpetuating, often in spite of themselves. This is a deep insight, and one that, it seems to me, has been powerfully put into practice by the Black Lives Matter movement. As this movement recognizes, there’s no single tyrant we could depose from office in order to end the problem; instead there’s an amorphous hydra of culture, something much harder to fight. And some of the struggle has to be with our own recalcitrant hearts, our own invaded consciousnesses.

A second fascinating insight is that power doesn’t just tell us what to do: it also tells us who to be. The culture we live in establishes identity categories, and we often end up understanding ourselves in relation to them. To take one of Foucault’s examples, same-sex desire has always existed, but the establishment of the category “gay” made a big difference to the way in which vast numbers of people understood their lives. These categories are sometimes empowering and sometimes limiting—and, I think, more subject to our control than Foucault sometimes admits—but always forces to be reckoned with.

There’s also plenty not to love in Foucault. His writing is often obscure (perhaps deliberately so!), sometimes contradictory, and rarely entirely precise. He bases quite a few of his claims on what appears to be historical evidence, but the historical evidence often turns out to be totally erroneous. (There was, for example, no “Great Confinement” in the Enlightenment: only small numbers of mental patients were locked in asylums.) For complicated but ultimately bad reasons, Foucault supported the regime of Ayatollah Khomeini. He had a penchant for exaggerating how terrible everything is, seeing a desire to control under every “apparent” act of benevolence. (Like other “hermeneuts of suspicion,” he enjoyed playing Eeyore, imagining a sinister underbelly beneath all human phenomena.) He claimed that at any given moment in history there is a single paradigm (or “episteme”) that ”defines the conditions of possibility of all knowledge”—never explaining why earlier ways of thinking often survive into later periods, or for that matter how he, Foucault, magically got to jump outside his own episteme in order to recognize this very fact. He once called truth “a useless notion, superfluous and contradicted on all sides,” its history being “the history of an error we call truth.” And he said that “it is not possible for power to be exercised without knowledge“—a claim about which many of today’s Americans would say: “if only!”

Foucault himself quietly retracted a lot of these claims toward the end of his career. All of a sudden, there were cases where apparent benevolence turned out to be—guess what?—real benevolence, not just a front for mind control. All of a sudden, there were cases where apparent self-fashioning turned out to be real self-fashioning, not just the unwitting internalization of social norms. All of a sudden, freedom was not always an illusion. Some of us might wish he had come to these eminently sensible realizations a bit earlier. But for all its very real flaws, Foucault’s thinking leaves a legacy that’s still worth taking seriously—not just in thought but also in action.