SUMMA THEOLOGICA. Thomas Aquinas
href="#ulink_a731b68e-c1f5-55e5-a572-c8611ca68640">Question [55], Article [1]). Now, the difference between heavenly and earthly bodies is this, that earthly bodies obtain their last perfection by chance and movement: while the heavenly bodies have their last perfection at once from their very nature. So, likewise, the lower, namely, the human, intellects obtain their perfection in the knowledge of truth by a kind of movement and discursive intellectual operation; that is to say, as they advance from one known thing to another. But, if from the knowledge of a known principle they were straightway to perceive as known all its consequent conclusions, then there would be no discursive process at all. Such is the condition of the angels, because in the truths which they know naturally, they at once behold all things whatsoever that can be known in them.
Therefore they are called "intellectual beings": because even with ourselves the things which are instantly grasped by the mind are said to be understood [intelligi]; hence "intellect" is defined as the habit of first principles. But human souls which acquire knowledge of truth by the discursive method are called "rational"; and this comes of the feebleness of their intellectual light. For if they possessed the fulness of intellectual light, like the angels, then in the first aspect of principles they would at once comprehend their whole range, by perceiving whatever could be reasoned out from them.
Reply to Objection 1: Discursion expresses movement of a kind. Now all movement is from something before to something after. Hence discursive knowledge comes about according as from something previously known one attains to the knowledge of what is afterwards known, and which was previously unknown. But if in the thing perceived something else be seen at the same time, as an object and its image are seen simultaneously in a mirror, it is not discursive knowledge. And in this way the angels know things in the Word.
Reply to Objection 2: The angels can syllogize, in the sense of knowing a syllogism; and they see effects in causes, and causes in effects: yet they do not acquire knowledge of an unknown truth in this way, by syllogizing from causes to effect, or from effect to cause.
Reply to Objection 3: Experience is affirmed of angels and demons simply by way of similitude, forasmuch as they know sensible things which are present, yet without any discursion withal.
Whether the angels understand by composing and dividing?
Objection 1: It would seem that the angels understand by composing and dividing. For, where there is multiplicity of things understood, there is composition of the same, as is said in De Anima iii, text. 21. But there is a multitude of things understood in the angelic mind; because angels apprehend different things by various species, and not all at one time. Therefore there is composition and division in the angel's mind.
Objection 2: Further, negation is far more remote from affirmation than any two opposite natures are; because the first of distinctions is that of affirmation and negation. But the angel knows certain distant natures not by one, but by diverse species, as is evident from what was said ( Article [2]). Therefore he must know affirmation and negation by diverse species. And so it seems that he understands by composing and dividing.
Objection 3: Further, speech is a sign of the intellect. But in speaking to men, angels use affirmative and negative expressions, which are signs of composition and of division in the intellect; as is manifest from many passages of Sacred Scripture. Therefore it seems that the angel understands by composing and dividing.
On the contrary, Dionysius says (Div. Nom. vii) that "the intellectual power of the angel shines forth with the clear simplicity of divine concepts." But a simple intelligence is without composition and division. Therefore the angel understands without composition or division.
I answer that, As in the intellect, when reasoning, the conclusion is compared with the principle, so in the intellect composing and dividing, the predicate is compared with the subject. For if our intellect were to see at once the truth of the conclusion in the principle, it would never understand by discursion and reasoning. In like manner, if the intellect in apprehending the quiddity of the subject were at once to have knowledge of all that can be attributed to, or removed from, the subject, it would never understand by composing and dividing, but only by understanding the essence. Thus it is evident that for the self-same reason our intellect understands by discursion, and by composing and dividing, namely, that in the first apprehension of anything newly apprehended it does not at once grasp all that is virtually contained in it. And this comes from the weakness of the intellectual light within us, as has been said ( Article [3]). Hence, since the intellectual light is perfect in the angel, for he is a pure and most clear mirror, as Dionysius says (Div. Nom. iv), it follows that as the angel does not understand by reasoning, so neither does he by composing and dividing.
Nevertheless, he understands the composition and the division of enunciations, just as he apprehends the reasoning of syllogisms: for he understands simply, such things as are composite, things movable immovably, and material things immaterially.
Reply to Objection 1: Not every multitude of things understood causes composition, but a multitude of such things understood that one of them is attributed to, or denied of, another. When an angel apprehends the nature of anything, he at the same time understands whatever can be either attributed to it, or denied of it. Hence, in apprehending a nature, he by one simple perception grasps all that we can learn by composing and dividing.
Reply to Objection 2: The various natures of things differ less as to their mode of existing than do affirmation and negation. Yet, as to the way in which they are known, affirmation and negation have something more in common; because directly the truth of an affirmation is known, the falsehood of the opposite negation is known also.
Reply to Objection 3: The fact that angels use affirmative and negative forms of speech, shows that they know both composition and division: yet not that they know by composing and dividing, but by knowing simply the nature of a thing.
Whether there can be falsehood in the intellect of an angel?
Objection 1: It would seem that there can be falsehood in the angel's intellect. For perversity appertains to falsehood. But, as Dionysius says (Div. Nom. iv), there is "a perverted fancy" in the demons. Therefore it seems that there can be falsehood in the intellect of the angels.
Objection 2: Further, nescience is the cause of estimating falsely. But, as Dionysius says (Eccl. Hier. vi), there can be nescience in the angels. Therefore it seems there can be falsehood in them.
Objection 3: Further, everything which falls short of the truth of wisdom, and which has a depraved reason, has falsehood or error in its intellect. But Dionysius (Div. Nom. vii) affirms this of the demons. Therefore it seems that there can be error in the minds of the angels.
On the contrary, The Philosopher says (De Anima iii, text. 41) that "the intelligence is always true." Augustine likewise says (Questions. 83, qu. 32) that "nothing but what is true can be the object of intelligence" Therefore there can be neither deception nor falsehood in the angel's knowledge.
I answer that, The truth of this question depends partly upon what has gone before. For it has been said ( Article [4]) that an angel understands not by composing and dividing, but by understanding what a thing is. Now the intellect is always true as regards what a thing is, just as the sense regarding its proper object, as is said in De Anima iii, text. 26. But by accident, deception and falsehood creep in, when we understand the essence of a thing by some kind of composition, and this happens either when we take the definition of one thing for another, or when the parts of a definition do not hang together, as if we were to accept as the definition of some creature, "a four-footed flying beast," for there is no such animal. And this comes about in things composite, the definition of which is drawn from