  The causal relationship that the agent intellect enjoys with respect to the soul of man raises one last question for Dietrich: to what extent if any is the intellect separated in its existence from man? This question of course had been debated in the schools by the generation of scholars that immediately preceded Dietrich. But it was still a question that attracted attention in his own day. There were philosophers then, as there probably always will be, who wanted to argue that the intellect was a function of the soul, having no existence outside of the soul. Dietrich, however, basing his position squarely upon an old Augustinian tradition, argued just the opposite. Separation is a characteristic of intellect as such, and in man it is identified with the “interiority” which Augustine claimed was not joined to the body as its form. Tétreau points out that Dietrich never attempts to prove his doctrine of separation, but assumes it on the basis of a passage in Aristotle’s De anima (III, 5, 430a17–18) where Aristotle claims that mind and its act of thought cannot be subjected to temporality. This, however, is not exactly accurate. It has already been shown that Dietrich has in mind Augustine’s notion of a separate interiority in man that he identifies with his agent intellect. But the fact that Dietrich does not offer a proof for his doctrine is not due to his appeal to the authority of Aristotle and Augustine. Rather, as Mojsisch shows, the separation of the intellect is due to its essential intellectuality. Since Dietrich claims that the agent intellect is intellect through its own essence, he need not demonstrate its property of separateness when it acts as efficient cause of the human soul. Separateness is a property of its essential intellectuality.