Chapter 086 - What Our Intellect Knows in Things Material and Immaterial

Our intellect cannot know individual material things primarily and directly, since its mode of understanding is by the abstraction of intelligible species from individual matter, and that which is abstracted from matter is universal. Hence the intellect apprehends universals directly, but particulars only indirectly, and as it were by some sort of reflection. And since the intellect abstracts species, it can only understand them by adverting to the phantasms in which it understands intelligible species. Thus the intellect knows individual sensible things through reflecting on these images and through sense.

The object of our intellect being such - i.e. the nature of material things - it follows that we cannot have an actual knowledge of the infinite; because faculties are proportioned to their object, and in material things nothing actually infinite is found. For the infinite is that from which whatever quantity be deducted there remains always more to take away; hence it cannot be understood actually, but only potentially, inasmuch as our intellect is not subject to the limits of corporeal matter and so is an infinite faculty. Nor can we know the infinite by habit, because such knowledge is arrived at by actual consideration, habit being formed by acts. Hence we should require to consider all the infinite, enumerating it according to the apprehension of succession, which is impossible.

Contingent things, as such, are known directly by sense and indirectly by the intellect through reflection from sense; but where they involve something necessary and universal the intellect apprehends them directly. Therefore, if we consider the universal conceptions of things, all sciences belong to the necessary; but if we consider the things themselves, some knowledge belongs to the necessary and some to the contingent.

Future things are known by the intellect by mode of reflection, for things which are subject to time are individual; but inasmuch as such conceptions are universal the intellect can apprehend them directly.

For the future may be generally known in two manners: either as it is in itself, and so is known to God only, Who knows all things at once by an eternal intuition; or according as things exist in their causes, and thus they may be foreknown by us, provided they be in their causes necessarily - as astronomers know eclipses. If they are only contingently in their causes they may be known by conjecture, more or less certainly according as the causes are more or less disposed towards the effects.