Aristotle believes that most “prophetic” dreams are coincidences based on the fact that the dreamer has no real participation in the story of the dream. We often mention things during conversation that later come to pass and this same phenomena occurs in dreams. Because the engine of both wakefulness and dreams is the brain, we understand why this has to be so. Again, because god does not communicate to the common people, their visions must be a random result of their physical temperament – “excitable and garrulous”. The common people have chance experiences where visions play a part in their slumber, like the gambler who plays even and odd.
Prophetic dreams are caused by the condition of sleep; the fact that there is less to disturb the body than during the day. There is no wind at night to disturb the senses and compete with the visions of our dreams.