De Divinatione per SomnumAristotle

De Divinatione per Somnum (On Divination in Sleep, also called On Prophesying by Dreams) is Aristotle's brief treatise in the Parva Naturalia on whether dreams can foretell the future. He treats the question with marked skepticism. If such dreams were sent by the gods, one would expect them to come to the best and wisest people; in fact they come to ordinary persons. Most so-called prophetic dreams are coincidences: a dream and a later event happen to match, without any causal link. Some dreams may arise from faint internal movements that daytime sensation masks, and that later become actual conditions of the body; in that limited sense a dream can signal what is already beginning. Others may start actions that fulfill themselves. Aristotle does not deny every connection between dream and waking event, but he refuses the claim that dreams are divine messages. The treatise sits with On Sleep and On Dreams as the natural account of nocturnal experience against both popular superstition and more pious theories of divine warning.