In an interview, Foucault responds:
“I am simply a Nietzschean, and I try as far as possible, on a certain number of issues, to see with the help of Nietzsche’s texts” (1989, 471).
Source: Foucault Live (Interviews, 1961-1984). Edited by Sylvère Lotringer. Translated by Lysa Hochroth and John Johnston. New York: Semiotext(e), 1989, p. 471.)
Related: Explaining Postmodernism: Skepticism and Socialism from Rousseau to Foucault.