Book 1, Chapter 29

60 “‘But many dreams are false.’ Or perhaps obscure to us. Still, let some be false: what do we say in answer to the true ones? Far more would come true if we went to sleep with our faculties unimpaired. As it is, loaded with food and wine, we see confusion and disorder. Consider what Socrates says in Plato’s Republic: ‘When people sleep, the part of the soul that shares in intellect and reason lies dormant and slack. But the part containing a certain ferocity and savage brutality, stupefied by immoderate eating and drinking, leaps up in sleep and tosses about without restraint. So every kind of vision assails it, stripped of intellect and reason: it seems to couple with its mother, or with anyone else, human or god, often even a beast; to slaughter someone and stain itself with impious blood; and to commit many foul and loathsome acts with recklessness and shamelessness.

61 “‘But suppose a person gives himself to rest after a healthy, moderate way of living and eating, having roused and quickened the part of the soul that thinks and judges, and fed it with a feast of good thoughts. Suppose the part nourished by pleasure is neither starved by want nor overflowing with excess—both commonly blunt the mind’s vision, whether nature lacks something or has an overflowing abundance. Suppose also that the third part of the soul, where anger blazes up, has been soothed and quenched. Then, with the two unruly parts subdued, the third, the seat of reason and intellect, will shine out, showing itself vigorous and keen for dreaming; and the visions that meet it in sleep will be peaceful and true.’ I have rendered Plato’s very words.

60 “‘But many dreams are false.’ Or perhaps they are obscure to us. Still, let some be false. What do we say, on the other side, about the true ones? We would have far more of these if we went to bed in a sound state. As it is, weighed down with food and wine, we see confused and jumbled things. Look at what Socrates says in Plato's Republic. He says, ‘When we are asleep, the part of the soul that shares in thought and reason grows numb and weak. But the part with a wild and savage fierceness, stupefied by too much drink and food, leaps up in sleep and throws itself about without restraint. Every sort of vision, empty of thought and reason, is put before it. It may dream of sex with its own mother, with any other human being or a god, often even with an animal. It may even slaughter someone and stain itself with sinful blood, or do many filthy and disgusting things, recklessly and shamelessly.

61 “‘But suppose someone goes to sleep after living and eating in a healthy, moderate way. He has roused and stirred up the part of his soul that thinks and plans, and has fed it with a feast of good thoughts. He has neither starved the part fed by pleasure nor filled it to overflowing. Either extreme tends to dull the mind's sharp vision, whether nature is deprived of something or has too much and overflows. He has also calmed and quenched that third part of the soul, where anger burns. Then, with the soul's two reckless parts held down, the remaining part, which thinks and reasons, will shine out and show itself lively and sharp for dreaming. The visions that come to him in sleep will then be calm and true.’ I have translated Plato's own words.