It may seem to be a long way from Blake's innocent talk of love and copulation to De Sade's need to inflict pain. And yet both are the outcome of a sexual mysticism that strives to transcend the everyday world. Simone de Beauvoir said penetratingly of De Sade's work that 'he is trying to communicate an experience whose distinguishing characteristic is, nevertheless its will to remain incommunicable'. De Sade's perversion may have sprung from his dislike of his mother or of other women, but its basis is a kind of distorted religious emotion.

p. 90 - The Origins of the Sexual Impulse (1963)