Nature, who for the perfect maintenance of the laws of her general equilibrium, has sometimes need of vices and sometimes of virtues, inspires now this impulse, now that one, in accordance with what she requires.
Source: Dolmanc?, in Philosophy in the Bedroom, Dialogue the Seventh (1795).
-- Marquis de Sade, (Jun 2 1740-1814), French novelist; He was the author of erotic writings that gave rise to the term sadism; wrote Justine.