(Yesterday I claimed we fail to understand either intelligence or intelligent desire – free choice – because we visualize it as the accident of a substance. Here is my translation of St. Albert’s argument against knowledge being either an accident or hylomorphic composite. Original is here, p. 498.)
Albertus Magnus
De intellectu et intelligibili
Liber Unus, Tractatus III, Caput 1.
How is the Intelligible in the Intellect?
…Since every act of understanding arises from an assimilation of the intellect and the intelligible, both must become one, but this unity is not entirely like subject and accident, nor is the unity like the the unity of matter and form, as is shown in De anima III. So we now turn to showing what exactly the unity is.
The best explanation is to look at how light is one with the colors that are drawn from it (abstrahuntur), since among all corporeal beings there are none in which the likeness to the incorporeal is clearer than light, which is why the agent intellect is said to be like light in De anima III. There are three things in light: the light, the lighting, and the luminous (lux, lucere, lumen). Considered in themselves, they seem to have either no difference, or very little, but if we consider them relative to each other they have tremendous differences between them. Light is the form of the luminous in a body giving light, lighting is the radiation of the form to something else, and the luminous is that form received by that which first illumines. Insofar as the color is drawn forth (abstractur) from the body and made spiritual in its nature (secundum esse spirituale) in the transparent medium it is not entirely like an accident in a subject, since an accident does not have the form and essence of an accident from the subject, but merely exists because of it (sed est tantummodo). Color, on the other hand, has its essence and form as a color from light, as is set down in De sensu et sensato.
Color is also not in light like a form in matter, because form is drawn out of matter (educitur) by the alteration of matter, and results in the generation of a composite thing. But color is not drawn out of the transparent medium in this way but is drawn out of the colored surface by a formal abstraction (abstractione formali) like a shape from a signet ring.
Again, form has material existence in the matter in which it is, but color in the transparent medium has a spiritual nature and not a material one, because the change of the transparent medium is immediate, as is true of [the light, the lighting and the illumined]. If we say the intellect is a light which exists in itself, then the intellect, the intelligible, and its own self-intelligibility do not differ from each other. In understanding that which receives its own intellectual light it understands its own act of knowing, and in understanding anything intelligible, it understands both itself and its proper action.
We need to visualize the known and the intelligible in the same way, because it exists in itself and it is abstracted from things, and when it exists in the light of the intellect it exists in that which gives it an actual intelligible form, and not as an accident in a subject or as a form in matter. It befits its spiritual nature that when abstracted from things it is neither an accident, nor a substance according to the fullest sense of the term (verissimas acceptiones) nor is it a difference or species of being, unless we take being in an extended sense (secundum quid). Intentions are, rather, certain intentions of beings taken from the power of their own agent causes: for just as it is in the power of light to confer existence to colors it is in the power of the intellect to confer existence to intelligible things taken according to the act of understanding.
It should be clear from this that the intellect understands its act of understanding by no operation or action other than understanding its own intelligible things, and that it understands itself by understanding any intelligible. The cause of this is what was already said, that the intellect pours forth (sonat) the incorporeal light of the intellectual nature, and it has the same form in itself whether it is received in some nature to be known, or remains in itself, or is received or terminated above the intelligible. That said, if any of these is referred to each other, they differ according to the things to which they are referred.