There is a scene in Robert Mullan’s Mad To Be Normal, a biopic of the Scottish psychiatrist R. D. Laing (played by David Tennant), in which the controversial figure is being interviewed on American radio during one of his promotional cross-Atlantic trips. While the room’s young, rapt audience look on, the broadcaster introduces Laing with a string of hyperbolic accolades, calling him an “acid Marxist” and, outrageously, a “white Martin Luther King”, whose revolutionary approach to treatment has enamoured the 60s counter-cultural spirit, and guaranteed him a spot on every dorm room bookcase in the United States. Eager for a…