"The Marxist theory of ideology . . . survives in the work of Michel Foucault, and other intellectuals, notably in The Order of Things (1966) and in his witty essays on the origins of the prison and the mad-house. These are exuberant exercises in rhetoric, full of paradoxes and historical fabrications, sweeping the reader along with a kind of facetious indifference to the standards of rational argument. Instead of argument, Foucault sees 'discourse'; in the place of truth he sees power. In Foucault's view, all discourse gains acceptance by expressing, fortifying and concealing the power of those who maintain it; and those who, from time to time, perceive this fact are invariably imprisoned as criminals or locked away as mad-- a fate that Foucault himself unaccountably avoided.
Foucault's approach reduces culture to a power-game, and scholarship to a kind of refereeing in the endless 'struggle' between oppressed and oppressing groups. The shift of emphasis from the content of an utterance to the power that speaks through it leads to a new kind of scholarship, which by-passes entirely questions of truth and rationality, and can even reject those questions as themselves ideological.
The pragmatism of the late American philosopher Richard Rorty is of similar effect. It expressly set itself against the idea of objective truth, giving a variety of arguments for thinking that truth is a negotiable thing, that what matters in the end is which side you are on. If a doctrine is useful in the struggle that liberates your group, then you are entitled to dismiss the alternatives."
Roger Scruton, "The great swindle: From pickled sharks to compositions in silence, fake ideas and fake emotions have elbowed out truth and beauty," Aeon Magazine, December, 2012