Colin Koopman at Aeon Magazine:
For his part, however, Foucault moved on, somewhat singularly among his generation. Rather than staying in the world of words, in the 1970s he shifted his philosophical attention to power, an idea that promises to help explain how words, or anything else for that matter, come to give things the order that they have. But Foucault’s lasting importance is not in his having found some new master-concept that can explain all the others. Power, in Foucault, is not another philosophical godhead. For Foucault’s most crucial claim about power is that we must refuse to treat it as philosophers have always treated their central concepts, namely as a unitary and homogenous thing that is so at home with itself that it can explain everything else.