 Alexander of Aphrodisias is an adherent of Aristotle’s philosophy, best known for his extensive commentaries on Aristotle’s texts. In his treatise On Fate, Alexander develops an Aristotelian theory on human freedom in reaction to the Stoics’ clearly determinist and compatibilist theory. Alexander’s theory is based on what Aristotle says, and he claims simply to be presenting Aristotle’s views. But Alexander’s treatment takes many elements of Aristotle, which on their own can be read as either compatible with causal determinism or incompatible with causal determinism, and develops them in incompatibilist ways. Alexander thinks that causal determinism is incompatible both with effective deliberation and with the sort of control over our actions needed for moral responsibility.