Does the human intelligence know its own act—know that it knows? In God, knowing and being are one. Although this is not true of the angelic intelligence, nevertheless with an angel the prime object of knowledge is his own essence. With one and the same act an angel knows that it knows, and knows its essence. But the primal object of the human intelligence is neither its knowledge (knowing, intelligere) nor its essence, but something extrinsic, to wit, the nature of the material thing. Hence that is the first object known by the human intelligence; and next is known its own actus, by which that first object is known. Likewise the human intelligence knows the acts of will. An act of will is nothing but a certain inclination toward some form of the mind (formam intellectam) as natural appetite is an inclination toward a natural form. The act of will is in the knowing mind and so is known by it.
So far as to how the soul knows material things, which are below it, and its own nature and qualities. It is another question whether the soul knows those things which are above it, to wit, the immaterial substances. Can the soul in the state of the present life know the angels in themselves? With lengthy argument, differing from Plato and adhering to Aristotle, Thomas proves the negative: that in the present life we cannot know substantias separatas immateriales secundum seipsas. Nor can we come to a knowledge of the angelic substances through knowing material things.
“For immaterial substances are altogether of another nature (ratio) from the whatnesses (quidditates) of material things; and however much our intelligence abstracts from matter the essence (quidditas) of the material thing, it will never arrive at anything like an immaterial substance. And so, through material substances, we cannot know immaterial substances perfectly” (Qu. lxxxviii. Art. 2).
Much less can we thus know God.
The discussion hitherto has been confined to the intellectual capacities of souls united to their bodies. As to the knowledge which the “separated” soul may have, other considerations arise akin to those touching the knowledge possessed by the separated substances called angels. Is the separated soul able to know? Thomas has shown that so long as the soul is joined to the body it cannot know anything except by turning itself to images. If this were a mere accident of the soul, incidental to its existence in the body, then with that impediment removed, it would return to its own nature and know simply. But if, as we suppose, this turning to images is of the nature of the soul, the difficulty grows. Yet the soul has one mode of existence when united to the body, and another when separated, but with its nature remaining. Souls united to bodies may know through resort to images of bodies, which are in the bodily organs; but when separated, they may know by turning to that which is intelligible simply, as other separate substances do. Yet still this raises doubt; for why did not God appoint a nobler way for the soul to know than that which is natural to it when joined to the body? The perfection of the universe required that there should be diverse grades among intellectual substances. The soul is the lowest of them. Its feeble intelligence was not fit to receive perfect knowledge through universal conceptions, save when assisted by concrete examples. Without these, souls would have had but a confused knowledge. Hence, for their more perfect knowledge of things, they are naturally united to bodies, and so receive a knowledge from things of sense proper to their condition; just as rude men can be led to know only through examples. So it was for a higher end that the soul was united to the body, and knows through resort to images; yet, when separated, it will be capable of another way of knowing.[606]
Separated from the body, the soul can know itself through itself. It can know other separated souls perfectly, but the angels, who are higher natures, only imperfectly, at least through the knowledge which the separated soul has from its nature; but that may be increased through grace and glory. The separated soul will know natural objects through the species (ideas) received from the inflowing divine light; yet less perfectly than the angels. Likewise, less universally than angels, will separated souls, by like means of species received from the divine light, know particular things, and only such as they previously knew, or may know through some affection or aptitude or the divine decree. For the habit and aptitude of knowledge, and the knowledge already acquired, will remain in the separated soul, so far as relates to the knowledge which is in the intellect, and no longer in the lower perceptive faculties. Neither will distance from the object affect the soul’s knowledge, since it will know through the influx of forms (species) from the divine light.
“Yet through the cognition belonging to their nature, separated souls do not know what is doing here below. For such souls know the particular and concrete (singularia) only as from the traces (vestigia) of previous cognition or affection, or by divine appointment. And the souls of the dead by divine decree, and in accordance with their mode of existence, are separated from the intercourse of the living and joined to the society of spiritual substances. Therefore they are ignorant of those things which are done among us.”
Nevertheless, it would seem, according to the opinions of Augustine and Gregory, “that the souls of the saints who see God know all that is done here. Yet, perfectly joined to the divine righteousness, they are not grieved, nor do they take part in the affairs of the living, save as the divine disposition requires.”
“Still the souls of the dead are able to care for the affairs of the living, although ignorant of their condition; just as we have care for the dead, though ignorant of their state, by invoking the suffrages of the Church. And the souls of the dead may be informed of the affairs of the living from souls lately departed hence, or through angels or demons, or by the revealing spirit of God. But if the dead appear to the living, it is by God’s special dispensation, and to be reckoned as a divine miracle” (Qu. lxxxix. Art. 8).
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