Quote from : American Fantastic Tales: Terror and the Uncanny from the 1940's Until Now Book

The clown figure has had so many meanings in different times and cultures. The jolly, well-loved joker familiar to most people is actually but one aspect of this protean creature. Madmen, hunchbacks, amputees, and other abnormals were once considered natural clowns; they were elected to fulfill a comic role which could allow others to see them as ludicrous rather than as terrible reminders of the forces of disorder in the world. But sometimes a cheerless jester was required to draw attention to this same disorder, as in the case of King Lear's morbid and honest fool, who of course was eventually hanged, and so much for his clownish wisdom. Clowns have often had ambiguous and sometimes contradictory roles to play. ("The Last Feast Of The Harlequin")