A difficulty: Since all knowledge, as it is the knowing mind, is a likeness of the thing known, and one separately subsistent intelligence is like another generically, but differs from it in species (Chap. XCIII), it appears that one does not know another in species, but only so far as the two meet in one common ratio, that of the genus.
Reply. With subsistent beings of a higher order than we are, the knowledge contained in higher generalities is not incomplete, as it is with us. The likeness in the mind of 'animal,' whereby we know a thing generically only, yields us a less complete knowledge than the likeness of 'man,' whereby we know an entire species. To know a thing by its genus is to know it imperfectly and, as it were, potentially; to know it by its species is to know it perfectly and actually. Holding as it does the lowest rank among subsistent intelligences, our intellect stands in such pressing need of particular detailed likenesses, that for every distinct object of its knowledge it requires a distinct likeness in itself: hence the likeness of 'animal' does not enable it to know 'rational,' consequently not 'man' either, except imperfectly. But the intellectual presentation in an intelligence subsisting apart is of a higher power, apt to represent more, and leads to a knowledge, not less perfect, but more perfect. By one presentation such an intelligence knows both 'animal' and the several specific differentias which make the several species of animals: this knowledge is more or less comprehensive according to the hierarchical rank of the intelligence.* We may illustrate this truth by contrasting the two extremes, the divine and human intellect. God knows all things by the one medium of His essence; man requires so many several likenesses, images or presentations in the mind, to know so many several things. Yet even in man the higher understanding gathers more from fewer presentations: slow minds on the other hand need many particular examples to lead them to knowledge. Since a separately subsistent intelligence, considered in its nature, is potentially open to the presentations whereby 'being' in its entirety (totum ens) is known, we cannot suppose that such an intelligence is denuded of all such presentations, as is the case with the potential intellect in use ere it comes to understand.* Nor again can we suppose that this separately subsistent intelligence has some of these presentations actually, and others, potentially only. For separate intelligences do not change (Chap. XCVII); but every potentiality in them must be actualised. Thus then the intellect of the separately subsistent intelligence is perfected to the full extent of its capacity by intelligible forms, so far as natural knowledge goes.*
2.97 : That the Mind of an Intelligence Subsisting apart is ever in the act of understanding
2.99 : That Intelligences Subsisting apart know Material Things, that is to say, the Species of Things Corporeal