Question Nine: The Communication of Angelic Knowledge

Does one angel illumine another?
Is an inferior angel always illumined by a superior angel or is he sometimes illumined directly by God?
Does one angel cleanse another when he illumines him?
Does one angel speak to another?
Do the inferior angels speak to the superior?
Is a determinate local distance required in order that one angel can speak to another?
Can one angel speak to another in such a way that others will not know what he is saying?


This question treats the communication of angelic knowledge by illumination and speech;

and in the first article we ask:

Does one angel illumine another?

[Parallel readings; S.T., I, 106, 1; 111, 1; 1I Sent., 9, 1, 2; 11, 1, 2; Comp. Theol., I, c. 126.]


It seems not, for

1. As Augustine says,’ only God can perfect a mind. But the illumination of an angel is, in a way, a perfecting of the mind of the person illumined. Hence, only God can illumine an angel.

2. There are no lights in angels other than those of nature and of grace. Now, one angel does not illumine another by the light of nature, because every angel has his natural powers directly from God, nor does one angel illumine another by the light of grace, because grace also comes directly from God alone. Consequently, one angel cannot illumine another.

3. As a body is related to material light, so is a spirit related to spiritual light. Now, a body illuminated by a very bright light is not illuminated simultaneously by a weaker light. For example, air illuminated by the light of the sun is not illuminated at the same time by the moon Consequently, since God’s spiritual light surpasses any created light more than the light of the sun surpasses that of a star or of a candle, it seems one angel is not illumined by another, simply because all angels are illumined by God.

4. If one angel illumines another, he does this either through a medium or directly. But he cannot do it directly, because then he would have to be joined directly to the angel he is to illumine; and only God can be joined to minds in this manner. On the other hand, he canno illumine another angel through a medium. He cannot illumine by means of a material medium, because such a medium cannot receive a spiritual light. Nor can he illumine by means of a spiritual medium because this medium would have to be an angel, and then an infinite series would arise, and illumination would be utterly impossible, for it is impossible to pass through an infinite. And, if we finally arrive at a point where one angel directly illumines another, this has already been shown to be impossible. Consequently, it is impossible for one angel to illumine another.

5. If one angel illumines another, he does this by giving him eithe his own light or some other light. But he does not do it in the first man ner, because, in that case, one and the same light would be in two different illuminated beings; nor does he do it in the second manner, because that light then would have to be made by the higher angel and from this it would follow that he created that light, since such a light is not made out of matter. Therefore, it seems that one angel doe not illumine another.

6. If one angel is to be illurnined by another, then the illumined ange must be reduced from potency to act, because to be illumined is a kind of becoming. But whenever a thing is reduced from potency to act something in it must undergo corruption. Now, since nothing in an gels can corrupt, it seems that one angel is not illumined by another.

7. If one angel is illurnined by another, the light which one gives to the other is either a substance or an accident. Now, it cannot be a substance, because, as Aristotle says, when a substantial form is added to a thing, it changes the species of the thing, just as an added unit changes the species of a number; hence, it would follow that an angel, by the fact of being illumined, would undergo a specific change. Similarly this light cannot be an accident, because an accident does not extend beyond its subject. Hence, one angel does not illumine another.

8. Our sensible and intellectual vision needs light, because its object is only potentially visible and potentially intelligible, but, by means of light, becomes actually visible and actually intelligible. Now, the object of angelic knowledge is actually intelligible, because it is the divine essence itself or co-created species. Consequently, angels do not need intellectual light in order to know.

9. If one angel illumines another, he illumines him with respect to either natural or gratuitous knowledge. However, he does not illumine him with respect to natural knowledge, because the natural knowledge had by both higher and lower angels is made perfect through innate forms; nor does he illumine him with respect to the gratuitous knowledge by which angels know things in the Word, because all angels see the Word directly. Consequently, one angel does not illumine another.

10. For intellectual knowledge, all that is required is an intelligible form and an intelligible light. Now, one angel does not give another angel intelligible forms, which are co-created, nor does he give him an intelligible light, because every angel is illumined by God, as we read in Job (25:3): “Is there any numbering of his soldiers? and upon whom shall not his light arise?” Therefore, one angel does not illumine another.

11. The purpose of illumination is to dispel darkness. But there is no darkness or obscurity in angelic knowledge. Consequently, the Gloss reads: “In the region of intelligible substances,”—clearly a reference to the regions where angels dwell—“the mind sees truth clearly, without any corporeal images, and not obscured by the mists of false opinions.” Hence, one angel is not illumined by another.

12. An angelic intellect is more noble than the active intellect of our soul. But the active intellect of our soul only illumines; it is never illumined. Therefore, angels are not illumined.

13. We read the following in the Apocalypse (21:23): “And the city hath no need of the sun, nor of the moon, to shine in it. For the glory of God hath enlightened it...” The Gloss expounds this text as referring to the principal and minor Doctors of the Church. Therefore, since an angel is already a citizen of that city, he is illumined only by God.

14. If one angel illumines another, he does this either through the abundance of the light given to him by his nature or through the abundance of light given him gratuitously. Now, one angel cannot illumine another through the abundance of his natural light, because the angel who fell belonged to the highest angels, and possessed the highest natural gifts, which, as Dionysius says, remained with him in their full strength. Consequently, a demon would be able to illumine an angel, and this is clearly absurd. Nor does one angel illumine another through the abundance of light given him gratuitously, because some men still living possess more grace than the lower angels do; indeed, because of their grace, they will be elevated to the ranks of the higher angels. Hence, a man still living could illumine an angel, and this is equally absurd. Therefore, one angel does not illumine another.

15. Dionysius says: “To be illumined is to receive divine knowledge.” Now, divine knowledge can be only that knowledge which is about God or divine things; and, in either case, angels can receive such knowledge only fro in God. Consequently, one angel does not illumine another.

16. Since the potency of an angelic intellect is entirely terminated by means of innate forms, these forms suffice for an angel to know all that he can know. Consequently, an angel should not need to be illumined by a higher angel in order to know something.

17. All angels, or at least those belonging to different orders, differ specifically from one another. Now, nothing is illumined by a lig t belonging to another species; for example, a material thing is not illumined by a light that is spiritual. Therefore, one angel is not illumined by another.

18. The light of an angel’s intellect is more perfect than the light of our active intellect. But the light of our active intellect suffices for us to know all the species we receive from our senses. Therefore, the light of an angel’s intellect is also sufficient for an angel to know all his innate species; consequently, no other light need be added to him.

To the Contrary

1. Dionysius says that the angelic hierarchy is divided into “those who are illumined and those who illumine.” Therefore.

2. just as there is a hierarchy among men, so is there a hierarchy among angels. This is clear from what Dionysius has written. Now, among men, superiors enlighten inferiors. For example, St. Paul says in the Epistle to the Ephesians (3:8-9): “To me, the least of all the saints, is given this grace, to preach among the Gentiles the unsearchable riches of Christ, and to enlighten all men...” Therefore, superior angels likewise illumine inferior angels.

3. Spiritual light is more efficacious than material light. But higher bodies illumine lower bodies. Therefore, higher angels illumine lower angels.


We should discuss intellectual light in terms of its resemblance to material light. Now, material light is a medium by which we can see things, serving our sense of sight in two ways:first, it makes things actually visible that were previously only potentially visible; second, its nature helps the sense of sight to see. Consequently, light must be in the very composition of the organ.

Similarly, intellectual light can be said to be the power of knowing which the intellect possesses, or even that thing by which another thing becomes known to us. There are two ways, therefore, in which a person can be illumined by another:first, his intellect can be strengtheped for the acts of knowledge; second, it can be guided by something to the knowledge of some other thing. Both of these actions are found together in the intellect; and we have a clear case of both of them happening together when the medium which a person mentally conceives strengthens his intellect to see some things which it previously could not see.

Accordingly, one intellect is said to be illumined by another in so far as the latter gives it some medium of knowledge, which strengthens it, and enables it to know some things which it previously could not know. Now, among men this takes place in two ways. First, it takes place through speech, as happens when a teacher, by what he says, gives some medium to his student that strengthens the latter’s intellect, enabling him to know things which he previously could not. In this sense, a teacher is said to enlighten his pupil. Second, a person can be given a sensible sign, and this can lead him to the knowledge of some truth. In this sense, according to Dionysius, priests are said to enlighten the people, inasmuch as they display and administer to them the mysteries which lead them to divine truths.

Angels, however, do not arrive at the knowledge of divine truths by means of sensible signs; nor do they receive intellectual media in a successive and discursive way, as we do, but immaterially. This is also what Dionysius held; for, when showing how the higher angels are illumined, he writes: “The highest essences, the angels, contemplate, [not] by gazing on symbols that can be known by the senses or intellect, nor by being led to God by the elaborations found in the Scriptures, but by being filled with the higher light of spiritual knowledge.” Consequently, for one angel to be illumined by another means simply this, that, through something seen in a higher angel, a lower angel’s intellect is strengthened to know other things.

This can take place in the following manner. Just as among bodies, higher bodies are, as it were, act with respect to lower bodies (as fire is, with respect to air), so a higher spirit is act, as it were, with respect to lower spirits. Now, every potency is strengthened and made perfect by being joined to its act. For this reason, lower bodies are preserved in higher bodies, which are the place of the former. Similarly, therefore, the lower angels can be strengthened by their being connected with the higher, and this connection takes place through intellectual intuition. For this reason, the lower angels are said to be illumined by the higher.

Answers to Difficulties

1. Augustine is speaking of that ultimate perfecting by which the mind is perfected with grace; and grace comes directly from God.

2. The illumining angel does not make a new light of grace or of nature; he merely shares his light. For, since whatever is known is understood by means of an intellectual light, the known as known includes in its notion a shared intellectual light that has the power to strengthen the intellect. This is evident if we consider the teacher who gives his pupil a medium of demonstration in which the light of the active intellect is contained as in an instrument; for, as the Commentator says,” first principles are quasi-instruments of the active intellect; and the same is true of all second principles which contain their own means of demonstration. Consequently, when a higher angel shows his knowledge to another angel, the intellect of the latter is strengthened so that it knows what it previously did not. Hence, no new light of nature or of grace comes into existence in the enlightened angel, but the hghv that was there previously is strengthened by the light contained in the higher angel’s knowledge.

3. Material and spiritual light are not entirely similar. For all bodies can be illumined by any material light whatsoever, since all material light is equally related to all visible forms; but not all spirits can be illumined by any light whatsoever, because not all lights contain intelligible forms in the same manner. The supreme light contains intelligible forms that are more universal. Consequently, it is not sufficient for an inferior intellect to be illumined by a higher light, since such an intellect is proportioned to receive its knowledge through forms that are more particular. To be led to the knowledge of things, this intellect must be illumined by an inferior light, as, of course, takes place in the case of men. For example, a metaphysician knows all things in their universal principles. A doctor, however, considers things especially in their particulars; hence, he does not take his principles directly from a metaphysician but directly from a philosopher of nature, whose principles are less general than those of a metaphysician. However, the natural philosopher, who considers things more universally than the doctor does, can take the principles for his science directly from the metaphysician.

Consequently, since the intelligible characters of all things are united in the highest degree in the light of the divine intellect, as in a single most universal principle, the lower angels are not proportioned to receive knowledge through such a light, unless there is joined to them the light of the higher angels, in whom the intelligible forms are made less universal.

4. An angel illumines another angel, sometimes through a medium, sometimes without a medium. Illumination through a medium (which is, of course, spiritual) takes place, for example, when a very high angel illumines an angel that stands halfway in the angelic hierarchy, and when the latter, by means of the light given him by the first, illumines an angel in the lowest part of the hierarchy. On the other hand, illumination without a medium takes place when, for example, a superior angel illumines an angel existing immediately below him in the hierarchy. It is not necessary that the angel who illumines be directly joined to the mind of the angel who is enlightened; the two are joined together simply by the fact that one intuits the other directly.

5. The medium that is known by the lower angel is numerically the same as that which is known by the higher; butthe knowledge which the higher angel has of that medium is other than that which the lower angel has. Consequently, in some sense, it is the same light, and, in another sense, it is another light. But even in the sense that it is another light it does not follow that it is created by the higher angel, because things which do not exist substantially do not, properly speaking, come into existence, just as they do not exist substantially. For example, as we read in the Metaphysics, it is not color but a colored thing that comes into existence. Consequently, the angel’s light does not come into existence, but the illumined angel, from being potentially enlightened, becomes actually enlightened.

6. just as no form is removed but only the privation of light, namely, darkness, is removed when material illumination takes place, so does a similar removal take place in spiritual illumination. Consequently, it is not necessary for any corruption to take place when spiritual illumination occurs. There is merely a removal of a negation.

7. That light by which an angel is said to be illumincd is not one of his essential perfections but a second perfection, which is reduced to the genus of accidents. Moreover, it does not follow that the accident extends beyond its subject, because the knowledge by which the higher angel is enlightened is not numerically the same as that which is in the lower angel. Their knowledge is the same merely in so far as it has the same nature and belongs to the same species, just as the light which is in illuminated air and that which is in the illumining sun is specifically, but not numerically, the same.

8. It is true that through light a thing which was potentially intelligible becomes actually so, but this can happen in two ways. First, it may be that that which is in itself only potentially intelligible becomes actually intelligible. This happens in our knowledge. But in this respect an angelic intellect does not need light, for it does not abstract species from phantasms. Secondly, it may be that that which is potentially intelligible to some particular knower becomes actually intelligible to him. This takes place, for example, when the higher substances become actually intelligible to us, that is, when we arrive at knowledge of them by reasoning. It is for such knowledge that an angel’s intellect needs light, that is, so it can be led to the actual knowledge of those things which it knows only potentially.

9. The illumination by which one angel illumines another does not concern those things that belong to angels’ natural knowledge, because, in that case, all the angels would have perfect natural knowledge from the moment when they first existed—unless we held that the higher angels caused the lower, and this position is contrary to faith. It concerns, rather, the knowledge that is revealed to angels and the things that surpass their natural knowledge, for example, mysteries pertaining to the Church in heaven or on earth. Hence, Dionysius also speaks of a hierarchical action among angels. Moreover, it does not follow from thefact that all angels see the Word that, whatever the higher angels see there, the lower also see.

10. When one angel is enlightened by another, new species are not infused into him, but, by the very same species which he had previously, his intellect is strengthened through a higher light, and, in the manner described, it is enabled to know more things. Similarly, when our intellect is strengthened by divine or angelic light, from the same phantasms it can come to know more things than it could know if left unaided.

11. Although there is no obscurity or error in angels’ intellects, angels do not know things which surpass their natural powers of knowing. For this reason, they need light.

12. No matter how material a thing is, it does not receive something else according to what is formal in itself, but only according to what is material in it. For example, our soul does not receive an illumination according to its active intellect but only according to its possible intellect. Similarly, material things do not receive impressions according to their own forms but merely according to their own matter. Yet our possible intellect is more simple than any material form. Similarly, an angel’s intellect is illumined only with respect to that which it possesses potentially, even though it is more noble than our active intellect, which is not illumined.

13. That text should be understood as referring to the things that belong to the knowledge the blessed have. Without any intermediary God illumines all angels about these things.

14. The illumination of which we are speaking takes place through the light of grace, which perfects natural light. Moreover, it would not follow that a man, still in this life, could illumine an angel, because he possesses greater grace only virtually, not actually. He has merely grace, by which he can merit a more perfect state, just as, in the same sense, a colt, immediately after birth, is said to have greater strength than an ass, even though its strength is actually less.

15. When we say that to be illurnined is to receive divine knowledge, this knowledge is called divine merely because it has its origin in a divine enlightenment.

16. Innate forms are sufficient for an angel to know all that he can know naturally; but, to know those things that are above his natural powers, he needs a higher light.

17. It is not necessary for the intelligible lights existing in angels, who are specifically different, to be specifically different themselves. For example, color existing in bodies that are specifically different is nevertheless specifically the same. The same principle is especially true of the light of grace, which is specifically the same both in men and in angels.

18. The light of the active intellect is sufficient for us to know those things that can be known naturally; but, to know other things, we need a higher light, such as that of faith or of prophecy.



In the second article we ask:

Is an inferior angel always illumined by a superior angel or is he sometimes illumined directly by God?

[Parallel readings: S.T., I, 107, 3; II Sent., 3, 1, 3, ad 4; 9, 1, 29 ad 3-4.]


It seems that he is illumined directly by God, for

1. An inferior angel is in potency to receiving grace in his will and illuminations in his intellect. Now, he receives only as much grace from God as he is capable of receiving. Therefore, he receives only as much illumination from God as he is capable of receiving. Consequently, he is directly illumined by God, and not through an intermediate angel.

2. just as superior angels stand midway between God and the inferior angels, so do the inferior angels stand midway between superior angels and men. Now, the superior angels sometimes illumine us directly. For example, a Seraph illumined Isaiah (Isaiah 6:6). Consequently, the inferior angels also are sometimes illumined directly by God.

3. just as there is a definite order of spiritual substances, so is there also a definite order of material substances. But God’s power sometimes acts directly on material things, passing over intermediate causes. For example, He sometimes raises a person from the dead without the co-operation of a celestial body. Consequently, He sometimes illumines inferior angels without the services of superior angels.

4. Whatever a lower power can do a high power can. Therefore, if a higher angel can illumine a lower angel, God can certainly illumine the lower angel directly. Hence, it is not necessary that God’s illuminations should always be given to lower angels by means of higher.

To the Contrary

1. Dionysius says’ that God has established an unchangeable law that lower beings be led back to God through the mediation of higher beings. Consequently, God never directly illumines lower angels.

2. just as angels are, by their very nature, superior to bodies, so are the higher angels, by their very nature, superior to the lower. Now, in matters related to God’s rule over material things, He never causes anything to happen without the ministry of His angels. This is clear from what Augustine has written. Consequently, God likewise never causes anything to happen in lower angels without the ministry of the higher.

3. Lower bodies are not moved by higher except through media. For example, the earth is moved by the heavens through the mediation of air. Now, the order of spirits resembles that of bodies. Consequently, the highest spirits do not illumine the lower except by means of intermediate spirits.


Because of His goodness, God communicates His perfections to creatures according to their capacity. Consequently, He shares His goodness with them, not only so that they will be good and perfect themselves, but also so that they can, with God’s help, give perfection to others. Now, to give perfection to other creatures is the most noble way of imitating God. Hence, Dionysius says: “The most God-like of all actions is to cooperate with God.” On this principle rests the ordering of angels, according to which some illumine others.

There have, however, been several opinions on this ordering. Some4 think that this order is so firmly fixed that nothing can happen outside of it, and it is always and in all cases preserved. Others, however, concede that this ordering is stable, but say that, while events usually happen according to it, it is sometimes passed over by the action of necessary causes—as when, by God’s dispensation, even the natural course of things is changed, and a new cause springs into being, as clearly itakes place in miracles.

But the first opinion seems to be more logical for three reasons. First, it belongs to the dignity of higher angels that the lower should be illumined through them. It would detract from their dignity if the lower angels were sometimes illumined without their ministry. Second, the closer beings are to God, who is most unchangeable, the more unchangeable should they themselves be. For this reason, bodies here below, standing at a great distance from God, are sometimes defective in their natural action, while celestial bodies always preserve the motion prescribed by their natures. Consequently, it does not seem reasonable that the ordering of celestial spirits, who are closest to God, should sometimes be changed. Third, God does not make any change in the things of nature except for something better, namely, for something pertaining to grace or glory. But there is no state higher than the states of glory by which the orders of angels are distinguished from each other. Therefore, it does not seem reasonable that matters concerning the order of angels should sometimes be changed.

Answers to Difficulties

1. God gives grace and illuminations to angels according to their capacity—with this difference, however, that, because grace pertains to the will, He gives grace to all of them directly; for there is no ordering in angels’ wills whereby one could act upon another. But God’s illuminations descend from Him to the lowest angels by means of the angels standing at the top and middle of the hierarchy.

2. Dionysius gives two answers to this difficulty. First, the angel that was sent to cleanse the lips of the prophet belonged to the inferior angels, but, by equivocation, was called a Seraph since he cleansed the prophet’s lips by burning them with a glowing coal brought from the altar by tongs; hence, he was said to be a Seraph only because he burned or set on fire. Dionysius’ second answer is that this angel, belonging to a lower order, cleansed the lips of the prophet because he did not intend to summon him to himself but to God and a higher angel, since he acted by the power of both. This is why he showed the prophet the higher angel and God. Similarly, a bishop is also said to absolve a person when a priest absolves by the bishop’s authority. Following this interpretation, we need not say that this angel was called a Seraph by equivocation or that a Seraph illumined the prophet directly.

3. The course of nature can have a more noble state; hence, it is proper for it to be changed at times. But there is nothing more noble than the state of glory. Therefore, no parallel can be drawn.

4. It is not because of any defect in God’s power or in that of the higher angels that God and the higher angels illumine the lower through the mediation of angels between them and the lower angels. This order is kept merely to preserve the dignity and perfection of all; and this demands that many co-operate with God in the same action.



In the third article we ask:

Does one angel cleanse another when he illumines him?

[Parallel readings: S.T., I, 106, 2, ad I; I-II, 112, 1, ad 3; II Sent., 3, 3, 2. See also readings given for q. 9, a. 1.]


It seems that he does not, for

1. To be cleansed is to be freed from impurity. But there is no impurity in angels; consequently, one angel cannot cleanse another.

2. But it was said that this cleansing is not from sin but from ignorance or lack of knowledge.—On the contrary, since such ignorance cannot be the result of any sin in the beatified angels, for they have no sin, it must be the result of nature. Now, those things that are natural cannot be removed while the nature remains. Consequently, an angel cannot be freed of his ignorance.

3. Illumination dispels darkness. Now, the only darkness which makes sense in regard to angels is the darkness of ignorance or of lack of understanding. Consequently, if their ignorance is removed when they are cleansed, their being cleansed and their being illumined come to the same thing, and the two should not be distinguished.

4. But it was said that illumination is referred to the end-term, while cleansing is referred to the initial term.—On the contrary, in no way of taking them is there found a term that is other than the end-term or the initial term. Consequently, if those two hierarchical actions, purgation and illumination, are distinguished according as one is referred to the initial term and the other to the end-term, a third hierarchical action cannot be posited; but to deny such a third action is to oppose Dionysius, who places’ the action of perfecting third.

5. As long as a thing is in the state of progression, it is not yet perfect. But, as the Master of the Sentences says, angels’ knowledge grows in some way until judgment day. Hence, at the present time, one angel cannot perfect another.

6. Illumination is the cause of perfecting, just as it is the cause of cleansing. Now, a cause must be prior to its effect. Therefore, just as illumination precedes perfection, so does it also precede purgation if the purgation be from ignorance.

To the Contrary

Dionysius distinguishes and orders these actions in this manner, saying: “The hierarchical order is such that some angels are cleansed, others do the cleansing, some are illumined, others illumine, some are perfected, others do the perfecting.”


In angels those three actions pertain merely to their reception of knowledge; for this reason Dionysius says: “Purgation, perfection, and illumination are the reception of divine knowledge.” However, the distinction between them should be understood in the following manner. Two terms can be found in any generation or change, namely, the initial term and the end-term. Both, however, are found in different ways in different changes.

In some changes the initial term is something contrary to the perfection to be acquired. For example, blackness is the contrary of the whiteness acquired when a thing becomes white. On the other hand, sometimes the perfection to be acquired does not have a contrary directly, but the dispositions existing in the subject before the change are contrary to the dispositions ordered to the perfection to be introduced. This condition is found, for example, when a soul is infused into a body. Again, it sometimes happens that nothing is presupposed for the introduction of the form except a privation or negation. For example, in air that is to be illumined only darkness precedes; and this is removed by the presence of light.

Similarly, there is at times only one end-term. For example, the endterm of the process of whitening is whiteness only. At other times, there are two end-terms, one of which is directed to the other. This is clearly the case when elements undergo change: one end-term is a disposition which demands a form, the other is the substantial form itself.

Now, in the reception of knowledge, we find the diversity mentioned above with respect to its initial term, because sometimes, before a person receives knowledge, there exists in him an error contrary to it. Again, at times there are in him beforehand only contrary dispositions, such as impurity of soul, an immoderate occupation with senseobjects, or something of this nature. Again, at other times, there may be in him beforehand only a privation or negation of the knowledge, such as exists in us whose knowledge increases from day to day. It is in this last-named sense that we should understand the initial term of illumination in angels.

Moreover, we find that there are two end-terms in the reception of knowledge. The first is that by which the intellect is perfected in order to know something. This end-term may be either an intelligible form, an intelligible light, or any medium of cognition whatsoever. The second end-term is the knowledge itself, which follows; and this is the final term in the reception of knowledge.

In angels’ cleansing takes place through the simple removal of ignorance in the manner described; for this reason Dionysius says: “To receive divine knowledge is to be cleansed of ignorance.” The illuniination, however, takes place in the first end-term. Hence, Dionysius also says that angels are illumined in so far as something is manifested to them “through a higher illumination.” Finally, “perfection” takes place in the ultimate end-term; and, for this reason, Dionysius says: “They are perfected by the light of resplendent knowledge.” In other words, illumination and perfection are understood to differ as the informing of the sense of sight by a species of what is seen differs from the knowledge of the thing seen.

Drawing an analogy from the principles laid down above, Dionysius writes that the order of the deacons is to purify neophytes in the faith, that of priests is to illumine them, and that of bishops, to perfect them. He said this because deacons exercise their office over catechumens and those possessed by the devils; and, in these persons, there are dispositions contrary to illumination which are removed by the deacons’ ministry. The duty of priests, however, is to teach and communicate the mysteries of the faith to the people; for these are, as it were, means for leading us to God. Finally, the duty of bishops is to uncover the spiritual riches that were concealed in the mystical symbols.

Answers to Difficulties

1. As Dionysius says, the cleansing of angels is to be understood as a cleansing, not from any impurity, but from lack of knowledge.

2. A negation or defect is said to be natural in two senses. In the first, it is said to be natural because the presence of such a negation is, as it were, due to nature. For example, not having an intellect is natural to an ass. Now, this kind of natural defect is never removed as long as the nature itself remains. In the second sense, however, a negation is said to be natural because to have some certain perfection is not due to nature. This kind of a negation is found especially when a faculty of the nature is not able to acquire a perfection of the sort mentioned. Such natural defects can be removed. For example, the ignorance boys have is removed, and our lack of glory is removed by the bestowal of glory. Similarly, the ignorance angels have can be removed.

3. Illumination and cleansing are related to each other in the acquisition of knowledge by angels as generation and corruption are related in the acquisition of a natural form. Needless to say, generation and corruption arc one in so far as they are in one subject, but they differ in their formal character.

4. The reply is clear from what has been said.

5. In our proposition, perfection is not taken as referring to all the knowledge an angel has, but only to a single act of knowledge; and he is perfected by this when he is led to the knowledge of some particular thing.

6. just as form is, in some way, the cause of matter inasmuch as it gives matter actual existence, so, in some way, matter is the cause of form inasmuch as it sustains the form. Similarly, the things coming from form are, in a certain sense, prior to those coming from matter, but in the case of some the opposite is true. Now, because privation is related to matter, the removal of the privation is naturally prior to the introduction of the form according to the order in which matter is prior to form, namely, the order of generation. But the introduction of the form is prior according to that order in which the form is prior to matter, namely, the order of perfection. The same argument can be applied to the orders of illumination and perfection.



In the fourth article we ask:

Does one angel speak to another?

[Parallel readings: S.T., I, 107, 1; 108, 5, ad 5; 108, 6; 109, 3; II Sent., 11, 2, 3; In I Cor., c. 13, lect. 1 (P. 13:259b).]


It seems not, for

1. Commenting on the words of Job (28:17), “Gold or crystal cannot equal it,” Gregory says: “In heaven everyone will be seen by others as now he does not even see himself.” But while on earth person does not have to speak to himself in order to know his ow idea. Consequently, in heaven it will not be necessary for him to speak to another so that he can know it. Hence, speech is unnecessary for beatified angels.

2. In the same passage, Gregory writes: “When one’s face is seen, in the same instant, his conscience will be penetrated.” Therefore, in heaven speech is not required for one person to know another’s concept.

3. Referring to angels, Maximus writes as follows: “When spiritual creatures meet and leave each other, one knows far more clearly what the other wishes to convey than were they to speak to each other. For, in some way, they silently discuss things and communicate their thoughts to each other.” Now, since silence is opposed to speech, angels know what other angels want to signify, without having to speak.

4. All speech takes place through signs. Now, a sign must be some thing that can be sensed, because, as is said in the Sentences: “A sign is that which, besides impressing a species upon the senses, make something else known.” Consequently, since angels do not receive their knowledge from sensible things, they do not receive it by mean of signs, and, hence, not through speech.

5. A sign seems to be something that is more known to us but les known according to nature. Accordingly, the Commentator distinguishes between a demonstration through a sign and a perfect demonstration, the latter being a demonstration which is causal. Now, angels do not receive their knowledge from things posterior in nature, consequently, not from signs. Hence, they do not receive knowledge by means of speech.

6. In all speech the speaker must arouse his listener to attention to his words, which, in our case, are produced by the voice of the speaker. But to listen to words of this kind is impossible for an angel. Therefore, speech is likewise impossible for him.

7. As Plato says,” speech was given to us so we could know signs of others’ wills. But one angel knows the signs of another angel’s will by knowing himself, because these signs are spiritual, and, by the same knowledge, an angel knows all spiritual things. Hence, since one angel knows the spiritual nature of another angel by knowing himself in the same way he knows his will. Therefore, he has no need of speech.

8. The forms within an angelic intellect are ordered to the knowledge of things, as in God the intelligible characters of things are ordered to their production, for angels’ intellectual forms resemble these characters. Now, all things and whatever exists in a thing, whether it be interior or exterior, are produced by means of these intelligible characters. Therefore, when an angel knows another angel by means of the forms within his own intellect, he also knows all that is within that angel; and, as a consequence, he knows that angel’s thought. Hence, the same must be said as before.

9. We have two kinds of speech, namely, internal and external. Now, we do not say that there is external speech in angels, because, if this were true, angels would have to form vocal speech to speak to each other. However, as Anselm~ and Augustine” say, “Internal speech is nothing other than thought.” Therefore, it is not necessary to assert that there exists in angels any kind of speech other than thought.

10. Avicenna says that we speak because we have a multitude of desires. This evidently arises from our many needs, because, as Augustine remarks, we desire a thing only if we do not have it. Now, since we cannot say that angels need many things, we cannot say that they speak to one another.

11. One angel cannot know another’s thought through its essence, because it is not present through its essence, to the other’s intellect. Hence, he must know the other’s thought by means of a species. Now, of himself, an angel is able to know, by means of innate species, all that naturally exists in another angel. For the same reason, therefore, through these same species he knows all that takes place by the will of the other angel. Hence, it does not seem necessary to affirm the exist ence of speech in angels in order that one can make his thought known to another.

12. Signs and nods are directed to the sense of sight, not to that of hearing, but speech is directed to the sense of hearing. Now, angels indicate their thought “by signs and nods,” for this is how the Gloss explains that verse in the first Epistle to the Corinthians (13:1): “If I speak with the tongues of men and of angels...” Therefore, angels do not use speech to communicate.

13. Speech is a motion of a cognitive power. Now, the motion of a cognitive power terminates in the soul, not in something outside. Therefore, through speech, an angel is not directed to the manifestation of his thought to another angel.

14. In all speech something unknown should be manifested by means of what is known. For example, we manifest our concepts by means of sensible sounds. Now, we cannot say that this is possible for angels, because, as Dionysius says, the nature of an angel, naturally known by other angels, has no shape. Hence, there is nothing in an angel’s nature that can be used to indicate what is not known about it. Consequently, for angels speech is impossible.

15. Angels are spiritual lights. But when light is seen it totally mamfests itself. Therefore, when an angel is seen, whatever is in him is totally known. Consequently, there is no need for speech among angels.

To the Contrary

11. We read in the first Epistle to the Corinthians (13:1): “If I speak with the tongues of men and of angels...” Now, tongues would be useless were there not speech. Consequently, angels speak.

2. As Boethius says, what a lower power can do a higher power also can. Now, men can reveal their thoughts to other men. Therefore, angels can do the same. However, to reveal one’s thought means to speak it. Hence, angels possess speech.

3. Damascene says: “In their discourses, which are not oral, angels tell each other what their wills are, and also what are their plans and their thoughts.” Now, discourse can be had only through speech. Therefore, angels possess the power of speech.


There must be some kind of speech among angels, for, as we proved carlier, one angel does not have direct and particular knowledge of what lies hidden in the heart of another; consequently, an angel must have some way of manifesting his thought to another. This way can be called angelic speech, for what we call speech in our own case is simply the manifestation of an interior word, which we mentally conceive.

We can understand how angels manifest their concepts to one another if we study the resemblance their speech has to things in nature, because, as Boethius says, forms in nature are quasi-images of immaterial things. Now, we find that a form exists in matter in three ways. First, it can exist imperfectly, that is, in a mode halfway between potency and act. This, for example, is how forms exist that are coming into existence. Second, it can exist in perfect act; and I mean a perfection such that the being having it is perfected in itself. Third, it can exist in perfect act in such a way that the being having the form also can communicate this perfection to another. Some things are bright themselves, but cannot illumine other things.

Intelligible forms exist in the intellect in a similar way. First, they can exist, as it were, halfway between potency and act, as a form possessed habitually. Second, they may exist in perfect act with respect to the knower. This is true when a knower actually thinks according to a form which he has within himself. Third, they may exist with a relation to some other being; and their transition from one being to the other (a transition, as it were, from potency to act) is made through the will. For the will of an angel causes him to turn actually to the forms he possesses, as it were, habitually; and, similarly, it makes his intellect actually more perfect with respect to the form within him, so that the angel is perfected, not only by this intellectual form itself, but also by the relation it has to another angel. When this takes place, his thought is perceived by the other angels; and, in this sense, one angel is said to speak to another.

We would have the same way of speaking if our intellect could be directed to intelligibles without having to have recourse to media; but, because it is the nature of our intelligence to receive from the senses, sensible signs are used to express our interior concepts, and by these signs we manifest our heart’s thoughts.

Answers to Difficulties

1. Gregory’s statement can be understood of both physical and spiritual vision; for in heaven, after the bodies of the saints have been glorified, a saint will be able to see with his physical eyes the interior of another’s body—something which is now impossible. It will be possible then, because glorified bodies will in some way be transparent. For this reason, Gregory compares them to glass. Similarly, one will be able to see with his spiritual eyes whether or not another person has charity, and, if so, how much he possesses—something which is likewise impossible now. From this it does not follow, however, that one, will be able to know the actual thoughts of another, because these depend on the will.

2. The conscience is said to be penetrated, but this is with respect to its habits, not to its actual thoughts.

3. In this statement, silence is opposed to oral speech such as we have, not to spiritual speech such as angels have.

4. A thing cannot be called a sign in the proper sense unless one can come to know something else as if by reasoning from it. In this sense, signs do not exist among angels, because, as we proved in the previous question, angels’ knowledge is not discursive. The signs we use are sensible, because our knowledge, which is discursive, has its origin in sense-objects. But we commonly call anything a sign which, being known, leads to the knowledge of something else; and for this reason an intelligible form can be called a sign of the thing which is known by its means. It is in this sense that angels know things through signs; and thus one angel speaks to another by means of signs, that is, through a species which actuates his intellect and puts it perfectly in relation to the other.

5. Although it is true that in natural things, whose effects are more known to us than their causes are, a sign is that which is posterior in nature, the notion of a sign, even properly speaking, is not such that a sign need be prior or posterior in nature, but only that it must be known previously by us. For this reason, at times we take effects as signs of causes, as when we judge health from the pulse, and at other times we take causes as signs of effects, as we take the dispositions of heavenly bodies as signs of stormy weather and rain.

6. When angels turn to others, as long as they put some of their intelligible forms into an actual relation to these others, the angels may be said to be arousing others’ attention to them.

7. It is true that an angel knows all spiritual things with the same kind of knowledge, that is, intellectually. But whether the knowledge of a thing comes through knowing oneself or through knowing something else concerns, not the type of knowledge, but only the manner in which this knowledge has been received. Hence, even if one angel knows the nature of another angel by knowing himself, it does not follow that he also knows the speech of the other in the same manner, because the thought of one angel is not as intelligible to another as his nature is.

8. That reasoning would follow if the intellectual forms in an angel were as efficacious for the knowledge of things as the intelligible characters of things in God are for their production. But this is not true, since a creature is not in any respect equal to God.

9. Although angels do not speak exteriorly as we do, namely, through sensible signs, they do speak exteriorly in another manner. The direction of their thoughts to other angels can be called exterior angelic speech.

10. A multitude of desires is said to be the cause of speech merely because desires give rise to a multitude of concepts and these concepts Vould be expressed only by signs that differ greatly. Now, animals have just a few concepts, which they can express by a few natural signs. But, since angels have many concepts, they need speech. However, their having many concepts is a sign of no desire other than that of one angel’s wanting to communicate his mental conception to another angel; and this desire is not a sign that he is imperfect.

11. One angel knows the thought of another through the innate species by which he knows that other angel, because through this same species he knows all that he knows about the other angel. Consequently, as soon as one angel relates himself to another angel according to an act of some form, the other angel knows his thought; and this depends on the will of the first angel. But the knowability of the angelic nature does not depend on the will of the angel. Therefore, angels do not need speech to know the nature of other angels but only to know their thoughts.

12. According to Augustine,” sight and hearing differ only exteriorly. Interiorly, in the mind, they are one and the same, because, in the mind, seeing and hearing do not differ. They differ only as they are in the external senses. Consequently, in angels, who have only minds, there is no difference between seeing and hearing. However, angelic speech gets its name from its resemblance to what takes place in us, for we receive our knowledge from others through our sense of hearing. Moreover, we can distinguish between angelic nods and signs in the following way:the species may be called signs, and the reference of the species to others, nods. But the very ability to do this is called their speech.

13. Speech is a motion of a cognitive power; however, the motion is not in the cognition but in the manifestation of the cognition. Hence, this motion must have an order to another being. For this reason, the Philosopher also says: “Speech exists in order that one can signify something to another.”

14. The essence of an angel does not have a material shape, but his intellect is, as it were, shaped by its intelligible forms.

15. Physical light manifests itself because of a natural necessity. Consequently, it manifests itself in the same way in regard to everything it contains. An angel, however, possesses a will; and his concepts cannot be manifested unless his will commands that they be manifested. This is why an angel needs speech.



In the fifth article we ask:

Do the inferior angels speak to the superior?

[Parallel readings: S.T., I, 107, aa. 2-3; In I Cor., c. 13, lect. 1 (P. 13:259b).]


It seems not, for

1. In its explanation of that verse in the first Epistle to the Corinthians (13:1), “If I speak with the tongues of men and of angels,” the Gloss reads as follows: “These tongues are the means by which the superior angels tell the inferior angels what they are first to learn about the will of God.” Consequently, speech, an act of the tongue, belongs only to the higher angels.

2. Whenever anyone speaks, something takes place in his listener. Now, in the higher angels, nothing can take place that is caused by the lower, because the higher are not in potency with respect to the lower; rather, the opposite is true, since the superior angels have more act and less potency. Consequently, the lower angels cannot speak to the higher.

3. To the notion of thought speech adds that of infusing knowledge. But the lower angels cannot infuse anything into the higher angels, because in that case they would be acting upon them, and this is impossible. Therefore, the lower do not speak to the higher angels.

4. To illumine is simply to manifest something unknown. Now, angelic speech is for the manifestation of something unknown. Therefore, angelic speech is an illumination. Hence, since inferior angels do not illumine superior angels, it would seem that they also do not speak to them.

5. The angel to whom another angel speaks is in potency to knowing what is expressed in the speech, and, by means of this speech, he comes to know it actually. Consequently, the angel speaking reduces the one spoken to from potency to act. Now, this is not possible for inferior angels with respect to superior angels, because in that case the inferior angels would be more noble. Hence, inferior angels do not speak to superior angels.

6. One person teaches another if he tells him something that he did not know. Consequently, if inferior angels speak to superior angels about their concepts, which the superior are ignorant of, it would seem that they teach the superior angels, and thus perfect them, since, as Dionysius says, to teach is to perfect. But this would be contrary to the hierarchical order, according to which inferior angels are perfected by superior.

To the Contrary

Gregory says: “God speaks to angels, and angels speak to God.” On the same principle, therefore, superior angels can talk to the inferior, and inferior to the superior.


To Iresolve this question satisfactorily, we must consider how, in angels, illumination differs from speech; and this can be done in the following way. An intellect falls short of knowing something for two reasons. First, the knowable object may be absent. For example, we do not know what has happened in past times or in remote places, if these happenings have not come to our attention. Second, there may be a defect in the intellect. That is, the intellect may not be strong enough to arrive at those truths which it already has in its possession, as, for instance, the intellect has all conclusions within itself in possessing first principles naturally known, but it does not know those conclusions unless it is strengthened by exercise or instruction. Properly speaking, therefore, speech is that by which a person is led to the knowledge of the unknown, because, through speech, something becomes present to him that would otherwise be absent. We have an evident example of this in our own case when one person shows another what the other did not see, and thus, in some sense, makes this thing present to him by nicans of speech. On the other hand, illumination takes place when the intellect is merely strengthened to know something above that which it already knew. We have explained this previously.

It should be noted, however, that both angels and men can have speech without illumination, because sometimes a thing is shown to us through speech only, and this does not strengthen our intellect in any way for knowing more. For example, one can recite to me merely a historical narrative, or one angel can reveal merely his thought to another angel; such matters can be equally known or not known by one having a strong intellect as well as by one having a weak intellect. But illumination in angels and men always has speech joined to it. For we illumine another person inasmuch as we give him some means by which his intellect is strengthened to know something, and this strengthening takes place through speech. In angels, this must also take place through speech, because the superior angel has his knowledge about things through forms that are more universal. Consequently, the inferior angel is not proportioned to receive knowledge from the superior unless the latter in some way distinguishes and divides his knowledge by conceiving within himself that about which he wishes to illumine in such a way that it will be comprehensible to the lower angel, and by manifesting this concept to him when he illumines him.

Consequently, Dionysius says: “In its providence, every intellectual essence divides and multiplies what it understands by one form, given to it by a godlike being, so that these divisions may act as guiding analogies for those below.”5 The same is true of the teacher who, seeing that his pupil cannot grasp things which he himself knows in the same way in which he knows them, makes a special effort to distinguish and multiply his knowledge by means of examples, so that his pupil will grasp his knowledge in this manner.

Hence, we must admit that angelic speech joined with illumination is found only when superior angels speak to inferior; but the other type of angelic speech is used both when inferior angels speak to superior and when superior speak to inferior.

Answers to Difficulties

1. The Gloss is referring here to angelic speech joined with an illumination.

2. The angel who speaks causes nothing in the angel to whom he is speaking. A change does take place, however, in himself; and, by reason of this change, he is known in the manner described above. Hence, there is no necessity for the angel speaking to infuse something into the one he is addressing.

3. The answer just given also solves the third difficulty.

4. The reply is evident from what has been said.

5. It is true that the angel to whom another angel speaks becomes an actual knower from being a potential knower; however, this takes place, not because he is reduced from potency to act, but because the angel who is speaking reduces himself from potency to act by making himself, with respect to some form, in perfect act according to an ordering to the other angel.

6. Properly speaking, teaching is applied only to those things which perfect an intellect. However, the fact that one angel knows the thoughts of another does not pertain to his intellectual perfection, just as it does not pertain to the perfection of my intellect if I learn about things that are not present to me and in no way concern me.



In the sixth article we ask:

Is a determinate local distance required in order that one angel can speak to another?

[Parallel readings: S.T., I, 107, 4; II Sent., 11, 2, 3, ad 3.]


It seems that it is, for

1.Whenever arrival and departure are involved, there is necessarily a determinate distance. But, as Maximus says, angels see each other’s thoughts as they approach and depart from one another. Therefore.

2. According to Damascene, an angel is where he operates. Consequently, if he speaks to another angel, he must be where his listener is; hence, some determinate distance is involved.

3, We read in Isaiah (6:3): “They cried one to another.” Now, the only reason for making cries is that a distance separates us from the one to whom we are speaking. Therefore, it seems that distance impedes the speech of angels.

4. Speech must be carried from the one speaking to the one listening. Now, this is not possible unless local distance separates the angel speaking from the one listening, because spiritual speech cannot be carried by a material medium.. Therefore, local distance impedes the speech of angels.

5. If Peter’s soul were on earth, it would know the events taking place here; but, since it is in heaven, it does not. Hence, the gloss of Augustine on Isaiah (6 3:16), “Abraham hath not known us,” says: “The dead”—even the saints—“do not know what the living are doing”—even their own sons. Consequently, local distance impedes the cognition of a separated soul, and, by the same reasoning, that of angels, and also their speech.

To the Contrary

The greatest possible distance separates paradise from hell; but the blessed and the damned can see each other, especially before the day of final judgment. This is clear from Luke’s account of Lazarus and the rich man (Luke 16:19-31). Consequently, no local distance impedes the cognition of a separated soul or that of an angel. By the same reasoning, it does not impede angels’ speech.


An agent acts according to its manner of existing. Hence, things that are material and circumscribed by place have actions that are material and circumscribed by place; and things that are spiritual act in a spiritual manner only. Consequently, because an angel as a knower is in no way circumscribed by place, the action of his intellect has no relation to place. Hence, since his speech is an operation of his intellect, local distance or proximity does not affect it. Therefore, one angel can understand the speech of another, whether that other be in a near or distant place—in the sense in which we say that angels are in place.

Answers to Difficulties

1. That arrival and departure should be understood, not according to place, but according to the angels’ turning to one another.

2. The statement that an angel is where he operates is to be under stood as referring to an operation which he carries out on some body; and this operation gets its place from that in which it terminates. Angelic speech, however, is not an operation of this kind. Hence, the argument does not follow.

3. The cries which the Seraphim are said to have made signify rather the magnitude of the things they spoke about, namely, the unity of God’s essence and the trinity of the persons; for they said: “Holy, Holy, Holy, the Lord God of hosts...” (Isaiah 6:3).

4. As already stated, the angel addressed does not receive anything from the one speaking; but, through species within himself, he knows the other angel as well as what he is saying. Consequently, there is no need of positing a medium by which something could be carried from one angel to another.

5. Augustine is speaking about the natural knowledge souls have. Through this, not even the saints can know what takes place here on earth. They can know these events, however, by means of the glory they have received. Gregory states, this explicitly when commenting on that verse in Job (14:2 1): “Whether his children come to honor or dishonor, he shall not understand.” But angels have a natural knowledge that is more perfect than that of the separated soul. Hence, no parallel can be drawn between a soul and an angel.



In the seventh article we ask:

Can one angel speak to another in such a way that others will not know what he is saying?

[Parallel readings: S.T., I, 107, 5.]


It seems not, for

1. For angelic speech, all that is required is an intelligible species and a turning to another angel. But, if that species and turning are known by one angel, so they are also known by another. Therefore, what an angel says is equally perceived by all.

2. Using the same “nods,” one angel can speak to all the angels. Consequently, if an angel knows the speech by which another angel addresses him, he will also know the speech by which he addresses others.

3. Whoever sees an angel perceives the species by which that angel understands and speaks. But angels always see one another. Therefore, one angel always knows what another is speaking, whether that angel is speaking to him or to some other angel.

4. If a man speaks, he is heard equally by all those standing at the same distance from him, unless there is some defect in one of the hearers, that is, if he is hard of hearing. Now, sometimes another angel is by nature or locally closer to the angel speaking than is the angel who is being addressed. Therefore, the angel speaking is heard by others than those whom he addresses.

To the Contrary

It seems inconsistent to assert that the angels cannot do something which we can do. But a man can confide to another what he has conccived in his heart in such a way that it remains hidden from others. Consequently, an angel is also able to speak to another without letting others know what he is saying.


As is clear from w hat was said previously, the thought of one angel comes to the knowledge of another after the manner of spiritual speech from the fact that the latter angel is actuated by a species not only subjectively but also with reference to the former; and this occurs by the will of the speaker.

Now, it is not necessary that things subject to the will should be related to all in the same way, but only as the will determines. Hence, spiritual speech is not related to all angels equally, but only as the will of the angel who is speaking shall determine. Consequently, if, by his own will, an angel is actualized with respect to some intellectual species which he has directed to only one other angel, his speech will be known by that angel only; and, if his species has an order to several, several angels will know it.

Answers to Difficulties

1. In angelic speech the turning or direction required is not one that is known but one that makes known. Hence, when one angel turns to another, his turning makes the other know his thought.

2. In general, there is one “nod” by which an angel speaks to all angels; but, in particular, there are as many “nods” as there are turnings to the different angels. Consequently, every angel knows according to the “nod” made to him.

3. Even though one angel sees another, he does not necessarily see the species by which the other angel is actually thinking, unless that other angel turns to him.

4. Human speech makes another person hear by an action physically necessary, namely, by driving air to the ear of the listener. But, as explained previously, this does not take place in angelic speech. Here, everything depends on the will of the angel speaking.


translation of

Thomas Aquinas,

Questiones Disputatae de Veritate

Volume 2, questions 10-20

translated by James V. McGlynn, S.J.

Chicago: Henry Regnery Company, 1953