Foucault

A right of sovereignty and a mechanics of discipline. It is, I think, between these two limits that power is exercised. The two limits are, however, of such a kind and so heterogeneous that we can never reduce one to the other. In modern societies, power is exercised through, on the basis of, and in the very play of the heterogeneity between a public right of sovereignty and a polymorphous mechanics of discipline.

I shall thus characterize the philosophical ethos appropriate to the critical ontology of ourselves as a historico-practical test of the limits that we may go beyond, and thus as work carried out by ourselves upon ourselves as free beings. p.47