Regarding Vrieberg’s view of the agent intellect and the idea that abstraction as generally understood is insufficient to explain intellectual knowledge because things, sensible impressions, particular images, etc. remain in the realm of the sensible order (and we need to “cross over” to the intelligible order) Gilson writes, “[t]he agent intellect can only work that transmutation because it is permanently turned toward God. We must not forget its nature: just like all other things, our intellect proceeds from the divine Ideas as an image and likeness of total being, and this is why the virtual knowledge of everything is contained in it. Its primary cognition of things is not discursive, but intuitive; it does not consider one object after another, but rather, in a single intuition, it knows its principle, acquires being and knows the totality of things” (History of Christian Philosophy in the Middle Ages, p. 436). Though Dietrich employs Aristotelian terminology, as Gilson points out, he is in actually reaffirming Plotinus. “In his treatise On the Intellect Dietrich expressly identifies this Plotinian agent intellect with the hidden recess of the mind (abditum mentis), or the more hidden depth (abstrusior profunditas) mentioned by Augustine in his De Trinitate” (Ibid., p. 437). Augustine of course was a great proponent of the doctrine of divine illumination (see, e.g., De Magistro). Regarding his own interpretation of divine illumination, Dietrich claims the following:
1) the hidden recess of the soul mentioned by Augustine, which is also the agent intellect, is a substance; 2) it is owing to this intellection that the hidden recess of the mind understands its own essence; 4) the intellect is by essence an exemplar and a similitude of being, in that it understands being and all things; 5) an intellect which is such by essence and is always in act, as the agent intellect is, knows all other things by its own essence, in the same way as it knows itself, and by the same simple act” (Ibid., p. 437).
Regarding the last point, Dietrich concludes that “the agent intellect is by essence the pattern of all being qua being, and, consequently, that is it in itself all being. By knowing itself, it knows all. In his own divine way, God does the same thing” (Ibid., p. 437). In spite of certain Neoplatonic similarities, according to Gilson, Dietrich tended to begin with Augustine and then made him say something beyond Augustine’s actual teaching (something more in the realm of M. Eckhart?).
I would be interested to hear from some of the Augustine scholars (or anyone so inclined) additional thoughts or insights in connection with the various ways in which Dietrich departs from Augustine’s teaching (given the citations from Gilson).