Concept
τύχη καὶ τὸ αὐτόματον
In the Physics Aristotle analyzes chance (tychē) and the spontaneous (to automaton) as real but derivative: they are accidental causes, what happens “by coincidence” when a process aimed at one end issues in another — as a man digging to plant finds buried treasure. Chance presupposes the regular causes and ends it interrupts; it is no power set beside providence, but the shadow cast where purposes cross.