Postmodernism means different things in different contexts. In philosophy the term refers to certain currents in French philosophy since the 1960s, including especially thinkers such as Jacques Derrida, Michel Foucault and Jean-François Lyotard. They have often been portrayed by critics as an academic axis of evil—corrupters of youth who propound a relativistic and cynical nihilism according to which “anything goes.”
The Old Guard in ancient Athens had a hard time distinguishing Socrates from the sophists. Both Socrates and the sophists challenged the complacent beliefs of the established order. Perhaps our situation is similar.