Foucault wasn't an anarchist, but he was far closer to that position than to any other. He pointed out that Freudian psychoanalysis was a creative discourse that helped to produce sexuality, a concept that didn't exist until a couple of centuries ago, where peoples' momentary sexual attractions and behaviors are essentialised into a few narrow identities placed at the center of who they are. Think of the homosexual who is supposed to do *everything* in a gay way. To walk gay, talk gay, dress gay, think gay, commit crime because they're gay. These identifications are internalised by the subjects of psychomedical authority, so they end up performing these identities to themselves and others. Freudian ideology becomes reality.
Freud's basic thinking is that sexuality exists prior to discourse as a multitude of dangerous passions produced by peoples' inhereted sexuality plus their family relations during childhood. These passions are repressed by civilisation and build up nervous energy that can be put to productive use, which he sees as pretty cool, although their repression also means that there's a lot of unbehagen in der kultur. Then Reich comes along and says 'It would be cooler if we could liberate sexuality from repression and in fact it is the way society treats sexuality that makes it dangerous. Also Orgone.'
Then Foucault says 'Fuck you both. I like leather-daddies as much as any straight man and Freud, you're creating what you're describing. (Despite having ambiguous elements in your work like 'basic bisexuality'. What the fuck?) Reich, liberation isn't finding better ways to conform to Freudian identities. Now if you'll excuse me I'm off to Frisco to get AIDS before I can write more masterpieces destroying your sad, Hippie worldview. Enjoy your irrelevance.'
But then most people still think in thoroughly Freudian terms and regard medicine as a neutral discourse. :(
Actually, it's worse than that. Thanks partially to Reichian gay liberation movements they think in terms of Freud *minus* upbringing (Born this way!), so absurdities like the whole world being neatly split into gay/straight/maybe-bi-but-probably-actually-gay-or-straight seem perfectly reasonable to most people. Despite being contradicted by even a cursory glance at history and anthropology.
You win this round, science.