Anyone who says this phrase with any amount of seriousness is surely a philistine, an anti-intellectual, and someone severely lacking in knowledge. How can anyone claim this when Berlioz wrote at least a portion of his famous "Symphony Fantastique" whilst high on opium, Coleridge wrote the "Kubla Khan" after an opium influenced dream, Francis Crick used acid, Freud snorted large amounts of coke, Steve Jobs dropped acid, Robert Louis Stevenson wrote "Dr Jekyll and Mr Hyde" on a six day coke binge, and there are countless other drug using geniuses like Baudelaire, Aldous Huxley, Philip K Dick, Hunter Thompson, William Burroughs, Ken Kesey, Jack Kerouac, David Bowie, Jimi Hendrix, Robert Plant, Charlie Parker, Martin Scorsese... the list is endless...