Because tvrannical desires are thus more or less "inhibited." their existence is evinced above all in dreams, the "sovereign route" to knowing what law, reason or better desires censor in the waking state - during sleep, to degrees proportionate to the strength or weakness of each person's repression, forbidden desires awaken as reason falls asleep. The mechanism described by Plato by which the inhibited returns anticipates Freudian description and metapsychology at every point. It is because, during sleep, the authority of supervision (Freud calls it the conscious mind or the superego; Plato, the careful, reasoning part of the soul, ready at the command: the intellect) - these sentinels and guardians of reason, known as good principles (cf. 560a and 591a) - slacken and rest; repressed desires are give free reign to satisfy their appetites; "the sleep of reason gives birth to monsters ...."