Thomas then argues that the intellectual substance is entirely immaterial. “Angelic substances are above our understanding. So our understanding cannot attain to apprehending them as they are in themselves; but only in its own fashion as it apprehends composite things.” These immaterial substances exist in exceeding great number, and each is a species, because there cannot be several immaterial beings of one species, any more than there could be separate whitenesses or many humanities. Angels in their nature are imperishable. For nothing is corrupted save as its form is separated from its matter. But these immaterial substances are not composed of matter and form, being themselves subsisting forms and indestructible. Brass may have and lose a circular shape; but the circular shape cannot be separated from the circle, which it is.

Thomas next shows (Pars prima, Qu. li.) that angels have no bodies by nature joined to them. Body is not of the ratio of intellectual substances. These (when perfect and not like the human soul) have no need to acquire knowledge through sensation. But though angels are intellectual substances, separate (separatae) from bodies, they sometimes assume bodies. In these they can perform those actions of life which have something in common with other kinds of acts; as speech, a living act, has something in common with inanimate sounds. Thus far only can physical acts be performed by angels, and not when such acts essentially belong to living bodies. Angels may appear as living men, but are not; neither are they sentient through the organs of their assumed bodies; they do not eat and digest food; they move only per accidens, incidentally to the inanimate motion of their assumed bodies; they do not beget, nor do they really speak; “but it is something like speech, when these bodies make sounds in the air like human voices.”

Dropping the sole remark, that scholasticism has no sense of humour, we pass on to Thomas’s careful consideration of the angelic relations to space or locality (Qu. lii. and liii.). “Equivocally only may it be said that an angel is in a place (in loco): through application of the angelic virtue to some corporeal spot, the angel may be said in some sense to be there.” But, as angels are finite, when one is said, in this sense, to be in a place, he is not elsewhere too (like God). Yet the place where the angel is need not be an indivisible point, but may be larger or smaller, as the angel wills to apply his virtue to a larger or smaller body. Two angels may not be in the same place at the same time, “because it is impossible that there should be two complete immediate causes of one and the same thing.” Angels are said, likewise equivocally, to move, in a sense analogous to that in which they are said to be in a place. Such equivocal motion may be continuous or not. If not continuous, evidently the angel may pass from one place to another without traversing the intervening spaces. The angelic movement must take place in time; there must be a before and after to it, and yet not necessarily with any period intervening.

Now as to angelic knowledge: De cognitione Angelorum. Knowing is no easy thing for man; and we shall see that it is not a simple matter to know, without the senses to provide the data and help build up knowledge in the mind. The function of sense, or its absence, conditions much besides the mere acquisition of the elements from which men form their thoughts. Thomas’s exposition of angelic knowledge and modes of knowing is a logical and consistent presentation of a supersensual psychology and theory of knowledge.

Entering upon his subject, Thomas shows (Qu. liv.) that knowing (intelligere) is not the substantia or the esse of an angel. Knowing is actio, which is the actuality of faculty, as being (esse) is the actuality of substance. God alone is actus purus (absolute realized actuality), free from potentiality. His substantia is His being and His action (suum esse and suum agere). “But neither in an angel, nor in any creature, is virtus or the potentia operativa the same as the creature’s essentia,” or its esse or substantia. The difficult scholastic-Aristotelian categories of intellectus agens and possibilis do not apply to angelic cognition (for which the reader and the angels may be thankful). The angels, being immaterial intelligences, have no share in those faculties of the human soul, like sight or hearing, which are exercised through bodily organs. They possess only intelligence and will. “It accords with the order of the universe that the supreme intellectual creature should be intelligent altogether, and not intelligent in part, like our souls.”

Quaestio lv., concerning the medium cognitionis angelicae, is a scholastic discussion scarcely to be rendered in modern language. The angelic intelligence is capable of knowing all things; and therefore an angel does not know through the medium of his essentia or substantia, which are limited. God alone knows all things through His essentia. The angelic intellect is made perfect for knowing by means of certain forms or ideas (species). These are not received from things, but are part of the angelic nature (connaturales). The angelic intelligence (potentia intellectiva) is completed through general concepts, of the same nature with itself (species intelligibiles connaturales). These come to angels from God at the same time with their being. Such concepts or ideas cover everything that they can know by nature (naturaliter). And Thomas proves that the higher angels know through fewer and more universal concepts than the lower.

Through this argument, and throughout the rest of his exposition of the knowledge of God, angel, and man, we perceive that, with Thomas, knowledge is superior and more delightful, as it is abstract in character, and universal in applicability. By knowing the abstract and the universal we become like to God and the angels; knowledge of and through the particular is but a necessity of our half-material nature.

Thomas turns now to consider the knowledge had by angels of immaterial beings, i.e. themselves and God (Qu. lvi.): “An angel, being immaterial, is a subsisting form, and therefore intelligible actually (actu, i.e. not potentially). Wherefore, through its form, which is its substance, it knows itself.” Then as to knowledge of each other: God from the beginning impressed upon the angelic mind the likenesses of things which He created. For in Him, from the beginning, were the rationes of all things, both spiritual and corporeal. Through the impression of these rationes upon the angelic mind, an angel knows other angels as well as corporeal creatures. Their natures also yield them some knowledge of God. The angelic nature is a mirror holding the divine similitude. Yet without the illumination of grace the angelic nature knows not God in His essence, because no created likeness may represent that.

As for material things (Qu. lvii.), angels have knowledge of them through the intelligible species or concepts impressed by God on the angelic mind. But do they know particulars—singularia? To deny it, says Thomas, would detract from the faith which accords to angels the ministration of affairs. This matter may be thought thus:

One observes that the whole scholastic discussion of universals lies back of arguments like these.

The main principles of angelic knowledge have now been set forth; and Thomas pauses to point out to what extent the angels know the future, the secret thoughts of our hearts, and the mysteries of grace. He has still to consider the mode and measure of the angelic knowledge from other points of view. Whatever the angels may know through their implanted natures, they know perfectly (actu); but it may be otherwise as to what is divinely revealed to them. What they know, they know without the need of argument. And the discussion closes with remarks on Augustine’s phrase and conception of the matutina and vespertina knowledge of angels: the former being the knowledge of things as they are in the Word; the latter being the knowledge of things as they are in their own natures.[603]

V

That the abstract and the universal is the noble and delectable, we learn from this exposition of angelic knowledge. We may learn the same from Thomas’s presentation of the modes and contents of human understanding. The Summa theologiae follows the Scriptural order of presentation;[604] which is doubtless the reason why Thomas, instead of passing from immaterial creatures to the partly immaterial creature man, considers first the creation of physical things—the Scriptural work of the six days. After this he takes up the last act of the Creation—man. In the Summa he considers man so far as his composite nature comes within the scope of theology. Accordingly the principal topic is the human soul (anima); and the body is regarded only in relation to the soul, its qualities and its fate. Thomas will follow Dionysius (Pseudo-Areopagite) in considering first the nature (essentia) of the soul, then its faculties (virtus sive potentiae), and thirdly, its mode of action (operatio).

Under the first head he argues (Pars prima, Qu. lxxv.) that the soul, which is the primum principium of life, is not body, but the body’s consummation (actus) and forma. Further, inasmuch as the soul is the principium of mental action, it must be an incorporeal principle existing by itself. It cannot properly be said to be the man; for man is not soul alone, but a composite of soul and body. But the soul, being immaterial and intellectual, is not a composite of form and matter. It is not subject to corruption. Concerning its union with the body (Qu. lxxvi.), “it is necessary to say that the mind (intellectus), which is the principle of intellectual action, is the form (forma) of the human body.” One and the same intellectual principle does not pertain to all human bodies: there is no common human soul, but as many souls as there are men.[605] Yet no man has a plurality of souls. “If indeed the anima intellectiva were not united to the body as form, but only as motor (as the Platonists affirm), it would be necessary to find in man another substantial form, through which the body should be set in its being. But if, as we have shown, the soul is united to the body as substantial form, there cannot be another substantial form beside it” (Qu. lxxvi. Art. 4). The human soul is fitly joined to its body; for it holds the lowest grade among intellectual substances, having no knowledge of truth implanted in it, as the angels have; it has to gather knowledge per viam sensus. “But nature never omits what is necessary. Hence the anima intellectiva must have not only the faculty of knowing, but the faculty of feeling (sentiendi). Sense-action can take place only through a corporeal instrument. Therefore the anima intellectiva ought to be united to such a body, which should be to it a convenient organ of sense” (Art. 5). Moreover, “since the soul is united to the body as form, it is altogether in any and every part of the body” (Art. 8).

It is a cardinal point (Qu. lxxvii.) with Thomas that the soul’s essentia is not its potentia: the soul is not its faculties. That is true only of God. In Him there is no diversity. There is some diversity of faculty in an angel; and more in man, a creature on the confines of the corporeal and spiritual creation, in whom concur the powers of both. There is order and priority among the powers of the soul: the potentiae intellectivae are higher than the potentiae sensitivae, and control them; while the latter are above the potentiae nutritivae. Yet the order of their generation is the reverse. The highest of the sensitive faculties is sight. The anima is the subject in which are the powers of knowing and willing (potentiae intellectivae); but the subject in which are the powers of sensation is the combination of the soul and body. All the powers of the soul, whether the subject be soul alone or soul and body, flow from the essence of the soul, as from a source (principium).

Thomas follows (Qu. lxxviii.) Aristotle in dividing the powers of the soul into vegetative, sensitive, appetitive, motor, and intellectual. In taking up the last, he points out (Qu. lxxix.) that intelligence (intellectus) is a power of the soul, and not the soul itself. He then follows the Philosopher in showing how intelligence (intelligere) is to be regarded as a passive power, and he presents the difficult Aristotelian device of the intellectus agens, and argues that memory and reason are not to be regarded as powers distinct from the intelligence (intellectus).

How does the soul, while united to the body (the anima conjuncta), (1) know corporeal things which are beneath it? (2) how does it know itself and what is in itself? and (3) how does it know immaterial substances which are above it? The exposition of these problems is introduced by (Qu. lxxxiv.) a historical discussion of the primi philosophi who thought there was nothing but body in the world. Then came Plato, seeking “to save some certain cognition of truth” by means of his theory of Ideas. But Plato seems to have erred in thinking that the form of the known must be in the knower as it is in the known. This is not necessary. In sense-perception the form of the thing is not in sense as it is in the thing. “And likewise the intelligence receives the species (Ideas) of material and mobile bodies immaterially and immutably, after its own mode; for the received is in the recipient after the mode of the recipient. Hence it is to be held that the soul through the intelligence knows bodies by immaterial, universal, and necessary cognition.”

Thomas sets this matter forth in a manner very illuminating as to his general position regarding knowledge:

Then Thomas again differs from Plato, and holds with Aristotle, that the intelligence through which the soul knows has not its ideas written upon it by nature, but from the first is capable of receiving them all (sed est in principio in potentia ad hujusmodi species omnes). Hereupon, and with further arguments, Thomas shows “that the species intelligibiles, by which our soul knows, do not arise from separate forms” or ideas.

To the converse question, whether intelligent cognition comes from things of sense, Thomas answers, following Aristotle: “One cannot say that sense perception is the whole cause of intellectual cognition, but rather in a certain way is the matter of the cause (materia causae).” On the other hand,

It is next queried whether the judgment of the mind is impeded through binding (per ligamentum) the senses. In view of the preceding argument the answer is, that since “all that we know in our present state, becomes known to us through comparison with sensible things, it is impossible that there should be in us perfect mental judgment when the senses are tied, through which we take cognizance of sensible things” (Qu. lxxxiv. Art. 8).

This entire argument shows in what firm Aristotelian manner, scholasticism, in the person of Thomas, set itself upon a basis of sense perception; through which it still pressed to a knowledge of the supersensible and abstract. In this argument we also see, as always with Thomas, that knowledge is perfect and blessed, the more immaterial and abstract are its modes. All of which will continue to impress us as we follow Thomas, briefly, through his exposition of the modus and ordo of knowing (intelligendi) (Qu. lxxxv.).

The first question is whether our mind knows corporeal things by abstracting the species from the images—the type from the particular. There are three grades of the cognizing faculty (virtutis cognoscitivae). The lowest is sensation, which is the act of a bodily organ. Its appropriate object is form as existing in matter. And since matter is the principle of individuation (i.e. the particularizing principle from which results the particular or individual), sense perception is confined to the particular. The highest grade of the cognitient faculty is that which is independent of bodily organs and separate from matter, as the angelic intelligence; and its object is form subsisting without matter. For though angels know material things, they view them only in the immaterial, to wit, themselves or God. Between the two is the human mind, which

It is next proved that the soul, through the intelligible species or forms abstracted from particulars, knows things which are outside the soul. In a way, intellection arises from sense perception; therefore the sense perception of the particular precedes the intellectual knowledge of universals. But, on the other hand, the intelligence, in coming to perfect cognition, proceeds from the undistinguished to the distinguished, from the more to the less general, and so knows animal before it knows homo, and homo before it knows Socrates. The next conclusion reads very neatly in scholastic Latin, but is difficult to paraphrase: it is that the intelligence may know many things at once (simul) per modum unius, but not per modum multorum; that is to say, the mind may grasp at once whatever it may grasp under one species, but cannot know a number of things at once which fall under different species.

Next as to what our mind knows in material things (Qu. lxxxvi.). It does not know the particular or singular (singularia) in them directly; for the principle of singularity in material things is the particular matter. But our mind knows by abstracting from such the species, that is, the universal. This it knows directly. But it knows singularia indirectly, inasmuch as, when it has abstracted the intelligible species, it must still, in order to know completely (actu), turn itself to the images in which it knows the species.

How does the anima intellectiva know itself, and those things which are in it (Qu. lxxxvii.)? Everything is knowable in so far as it is actually (in actu) and not merely potentially. So the human intelligence knows itself not through its essence, which is still but potential, but in so far as it has actually realized itself; knows itself, that is, through its actuality. The permanent qualities (habitus) of the soul exist in a condition between potentiality and actuality. The mind knows them when they are actually present or operative.

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.

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.

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.”

VI

We have thus traced Thomas’s view of the faculty of knowledge, the primary constituent of beatitude in God, and in angels and men. There are other elements which not only supplement the faculty of knowledge, but even flow as of necessity from a full and true conception of that faculty and its perfect energizing. These needful, yet supplementary, factors are the faculties of will and love and natural appetite; though the last does not exist in God or angel or in “separated soul.” The composite creature man shares it with brutes: it is of enormous importance, since it may affect his spiritual progress in this life, and so determine his state after death. Let us observe these qualities in God, in the immaterial substances called angels, and in man.

In God there is volition as well as intelligence; for voluntas intellectum consequitur; and as God’s being (esse) is His knowing (intelligere), so likewise His being is His will (velle).[607] Essentially alike in God and man and angel are the constituents of spiritual beatitude and existence—knowing, willing, loving. From Creator down to man, knowledge differs in mode and in degree, yet is essentially the same. The like is true of will. As to love, because passion is of the body, love and every mode of turning from or to an object is passionless in God and the angels. Yet man through love, as well as through willing and through knowing, may prove his kinship with angels and with God.

God is love, says John’s Epistle. “It is necessary to place love in God,” says Thomas. “For the first movement of will and any appetitive faculty (appetitivae virtutis) is love (amor).” It is objected that love is a passion; and the passionless God cannot love. Answers Thomas, “Love and joy and delight are passions in so far as they signify acts (or actualities, actus) of the appetitus sensitivi; but they are not passions when they signify the actus of the appetitus intellectivi; and thus are they placed in God” (Pars prima, Qu. xx. Art. 1).

God loves all existences. Now all existences, in so far as they are, are good. For being itself (esse) is in a sense the good of any thing, and likewise its perfection. It has been shown that God’s will is the cause of all things; and thus it is proper that a thing should have being, or good, in so far as it is willed by God. God wills some good to every existent thing. And since to love is nothing else than to will good to something, it is evident that God loves all things that are, yet not in the way we love. For since our will is not the cause of the goodness of things, but is moved by it as by an object, our love by which we will good to anything is not the cause of its goodness; but its goodness calls forth the love by which we wish to preserve and add to the good it has; and for this we work. But God’s love imparts and creates goodness in things.

The divine love embraces all things in one and the same act of will; but inasmuch as His love creates goodness, there could be no greater goodness in one thing than in another unless He willed greater good to one than to the other: in this sense He may be said to love one creature more than another; and in this way He loves the better things more. Besides love, the order of the universe proves God’s justitia; an attribute which is to be ascribed to Him, as Dionysius says, in that He grants to all things what is appropriate, according to the dignity of the existence of each, and preserves the nature of each in its own order and virtue. Likewise misericordia is to be ascribed to God, not as if He were affected by pitying sadness, but in that He remedies the misery or defects of others.

Thus far as to will and love in God. Next, as to these qualities in Angels. Have angels will? (Pars prima, Qu. lix.). Thomas argues: All things proceed from the divine will, and all per appetitum incline toward good. In plants this is called natural appetite. Next above them come those creatures who perceive the particular good as of the senses; their inclination toward it is appetitus sensitivus. Still above them are such as know the ratio of the good universally, through their intelligence. Such are the angels; and in them inclination toward the good is will. Moreover, since they know the nature of the good, they are able to form a judgment as to it; and so they have free will: ubicumque est intellectus, est liberum arbitrium. And as their knowledge is above that of men, so in them free will exists more excellently.

The angels have only the appetitus intellectivus which is will; they are not irascible or concupiscent, since these belong to the appetitus sensitivus. Only metaphorically can furor and evil concupiscence be ascribed to demons, as anger is to God—propter similitudinem effectus. Consequently amor and gaudium do not exist as passions in angels. But in so far as these qualities signify solely an act of will, they are intellectual. In this sense, to love is to will good to anything, and to rejoice (gaudere) is to rest the will in a good obtained. Similarly, caritas and spes, in so far as they are virtues, lie not in appetite, but in will; and thus exist in angels. With man the virtues of temperance and fortitude may relate to things of sense; but not so with angels, who have no passions to be bridled by these virtues. Temperance is ascribed to them when they temper their will according to the will divine, and fortitude, when they firmly execute it (Qu. lix. Art. 4).

In a subsequent portion of Pars prima (Qu. cx.) Thomas has occasion to point out that, as in human affairs, the more particular power is governed by the more universal, so among the angels.

Next Thomas considers the action of angels upon men, and shows that men may have their minds illumined by the lower orders of angels, who present to men intelligibilem veritatem sub similitudinibus sensibilium. God sends the angels to minister to corporeal creatures; in which mission their acts proceed from God as a cause (principio). They are His instruments. They are sent as custodians of men, to guide and move them to good. “To every man an angel is appointed for his guard: of which the reason is, that the guardianship (custodia) of the angels is an execution of divine providence in regard to men.” Every man, while as viator he walks life’s via non tuta, has his guardian angel. And the archangels have care of multitudes of men (Qu. cxiii.).

Thus Thomas’s, or rather, say the Christian doctrine as to angels, becomes a corollary necessary to Christian theism, and true at least symbolically. But—and this is the last point as to these ministering spirits—do the angels who love without passion, grieve and suffer when those over whom they minister are lost?

We come to man. He has will, and free will or choice, as the angels have. Will is part of the intellectual nature: it is as the intellectivus appetitus. But man differs from the angels in possessing appetites which belong to his sense-nature and do not perceive the good in its common aspects; because sense does not apprehend the universal, but only the particular.[608] Sometimes Thomas speaks of amor as including every form of desire, intellectual or pertaining to the world of sense. “The first movement of will and of any appetitive faculty (virtus) is amor.”[609] So in this most general signification amor “is something belonging to appetite; for the object of both is the good.”

Further distinguishing definitions are now in order:

Moreover, amor may be divided into amor amicitiae, whereby we wish good to the amicus, and amor concupiscentiae, whereby properly we desire a good to ourselves.

The Good is the object and, in that sense, the cause, of amor (Qu. xxvii.).

From this broad conception of amor the argument rises to amor in its purest phases, which correspond to the highest modes of knowledge man is capable of. They are considered in their nature, in their causes, and effects. It is evident whither we are travelling in this matter.

Caritas is one of the theological virtues, and as such Thomas treats it. To it corresponds the “gift” of sapientia, likewise a virtue bestowed by God, but more particularly regarded as the “gift” of the Holy Spirit. Caritas is set not in the appetitus sensitivus, but in the will. Yet as it exceeds our natural faculties, “it is not in us by nature, nor acquired through our natural powers; but through the infusion of the Holy Spirit, who is the amor Patris et Filii.” He infuses caritas according to His will; and it will increase as we draw near to God; nor is there any bound to its augmentation. May caritas be perfect in this life? In one sense it never can be perfect, because no creature ever can love God according to His infinite lovableness.