If the fire rages uncontrolled in a house, we call it a disastrous conflagration; if it burns in a smelting furnace, we call it a useful industrial force. In other words, our drives and impulses as they live within us are neither good nor bad, right nor wrong.

Sigmund Freud (1856–1939) Austrian psychoanalyst and neurologist

(Attributed)

Quoted in Helen Walker Puner, Freud: His Life and His Mind, ch. 10 (1947).