Tuesday, 31 January 2012

Question 55 - The Medium of the Angelic Knowledge

Why this Question Matters.

This question continues Aquinas’s inquiry into the knowledge that angels have and how they acquire it. Having disposed of the idea that knowledge or the power to have knowledge exhausts what an angel is, he now turns to the medium of an angel’s knowledge; by what does an angel know? When we think about human cognition, we think about our senses gathering sense data and about how our minds organize this information into knowledge. Angels do not have bodies and therefore do not have sense organs; therefore they cannot know things through sensing objects. Aquinas borrows concepts from human psychology (in particular, the notion of an intelligible species) to demonstrate how angelic knowledge comes about and how this process differs from what happens in humans and in God.

The Thread of the Argument

A1: Later on in the summa, in the “Treatise on Human Nature”, Aquinas is going to discuss human cognition in some depth. In this question, however, Aquinas wishes to discuss the way in which angels understand things and to compare this with the way that humans understand things. So we have to take some of the later discussion as understood here – and indeed this would already be part of the background education of the original readers of the summa.

When we perceive things, the sensitive part of the soul (and in particular, the imagination) presents phantasms to the intellect. A phantasm is a sort of internal representation of the external object of perception that has been assembled in the imagination from the raw materials detected by the senses. Thus, vision presents patches of coloured light and shade; hearing presents sounds, and so forth. If we take the example of perceiving a vase, the senses sense what is proper to them of the vase and the imagination constructs a phantasm of the vase from what the senses have perceived. The phantasm is then illuminated by the active intellect, abstracting what is universal about the vase from the phantasm of the particular vase. This process of abstraction results in what is termed an intelligible species being impressed upon the passive part of the intellect. This intelligible species is the form of the perceived object present in the mind in a different mode of being from the way that it is present in the original object; it forms the fundamental data by which we understand the quiddity (or what-ness) of the original object. The other faculties of the mind go to work, so to speak, on the intelligible species, together with a recollection of the phantasm from which it was formed, to provide an understanding of the original object.

Now, an angel is immaterial and therefore does not perceive things in the same way that we do. Angels do not have sense organs, for example, and therefore their knowledge of things is not built up from phantasms. How then do they know things? We recall that for God, the act of His intellect is His very substance (Ia.q14.a4); is angelic knowledge like God’s knowledge, known though their own substance? Or is their knowledge like our knowledge in that it is understood though intelligible species, even if those intelligible species are not constructed by an active intellect?

Aquinas argues for the latter solution by observing that that which the intellect understands provides a form for the actuality of the understanding intellect; the potentiality in the intellect to understand something is brought to actuality by the form of the thing understood. Now, an angel simply does not have all things within itself (otherwise it would be God), it does not have all forms within itself by which it can understand everything. But, the object of an intellect untrammelled by matter is being itself and therefore an angel has the power to understand everything. Therefore that understanding must be facilitated by forms made present to its intellect not through its substance. That is, it must be facilitated by intelligible species.

A2: Having argued that an angel understands things by means of intelligible species, Aquinas now has to answer the question of how those intelligible species come to be present to the intellect of the angel. In particular, even if the angel does not have sense organs by which to perceive things or an active intellect by which to construct intelligible species out of phantasms, is it still true that the intelligible species arrive at the angels intellect from the objects of perception themselves?

Aquinas’s position is, at first sight, strikingly odd and obscure: the intelligible species are not received from the things themselves but are connatural to the angels. What this means and why it is true is supported by two arguments. In the first case, Aquinas points out that there is a sort of hierarchy of being that we can observe both amongst material objects and amongst non-material objects. Things lower down the hierarchy of material objects do not achieve their perfection through their form alone but are perfected by the action of external agents, whereas objects higher up the hierarchy derive the perfection of their actuality from their form alone. Similarly, if we consider the lower intellectual creatures like man, they are brought to perfection not through their own forms but by the successive reception of intelligible species: humans learn and in so doing come closer to their perfection. Angels, being higher up the hierarchy, do not have to advance in this perfection by means of the successive accumulation of information; these intelligible species are already present to them as soon as they exist. Aquinas’s second argument puts it more bluntly: lower spiritual substances have a natural affinity with bodies and it is therefore connatural to them to attain intellectual fulfilment through these bodies. Higher spiritual substances, such as angels, have no such bodily affinity and they receive their intelligible species directly from God; it is connatural to them to have all the intelligible species relevant to their natural knowledge. For angels, knowledge is very much a matter of divine illumination; this illumination is mediated though intelligible species.

A3: A major element of the tradition that Aquinas inherits about the angels concerns their hierarchy. At the top of the hierarchy we have the Seraphim, Cherubim & Ophanim; next are the Dominions, Virtues & Powers; then the Principalities, the Archangels & the Angels. Aquinas asks in this article how these different levels in the hierarchy understand things; are the intelligible species by which the higher levels of the hierarchy understand more universal than those by which the lower levels of the hierarchy understand?

The basic tension in this question arises from the observation that a more specific knowledge about particulars would appear to be more perfect that a more general knowledge; but a more universal knowledge would seem more fitting to something higher up the hierarchy. These combined would seem to imply that those higher in the hierarchy would know less. Although this might be a quite normal state of affairs for a human organization, it seems quite inappropriate for a celestial hierarchy!

Aquinas points out that as God is completely simple He knows everything through one thing, His divine essence. As one proceeds down the celestial hierarchy from God, knowledge is obtained in progressively inferior ways, through more and more intelligible species. So, for an angel high up in the hierarchy, its knowledge is attained though fewer but more universal intelligible species. Aquinas gives us an analogy from everyday life: those with more developed intellects can grasp things with little explanation whereas those with weaker intellects need to be led through step by step. In reply to the objection about universality versus specificity of knowledge, Aquinas argues that knowing something “in a universal way” has two distinct senses. In the first sense we can certainly admit that to only know that something is an animal rather than that it is a human being is less perfect. On the other hand, we can consider a second sense that has to do with the way the knowing comes about; knowing specific particulars though a single universal medium is more perfect that knowing them through a complex of different media. After all, God’s knowledge provides an example of absolute perfection and is absolutely simple; we say that it is universal in this second sense.

Handy Concepts

  • In humans the active intellect constructs the intelligible species from the phantasms presented to it by the senses. The intelligible species is that by which the intellect comes to understand an object and provides the form that brings the intellect out of potentiality into actuality with respect to knowledge of this object.
  • Angels do not have bodies or active intellects, so they do not construct intelligible species in the way that we do. However, their knowledge is still based on intelligible species.
  • The intelligible species though which angels understand objects come direct from God rather than from the objects of knowledge.
  • Angels higher up the hierarchy have fewer, more universal, intelligible species by which they understand things.
  • A reading of the “Celestial Hierarchy” of Dionysius the Areopagite will prove useful for understanding the tradition that Aquinas inherits concerning the angels.


  • The idea that the angels obtain their intelligible species direct from God, rather than from the objects of perception themselves, might seem to cut them off from material part of creation. However, one might also argue that they are more intimately connected with material reality precisely because they do not receive their knowledge abstracted from the objects themselves. Modern philosophy argues about whether we can ever know things-in-themselves; the direct knowledge of the angels ensures that they, at least, can.
  • How perfectly do angels know things? The fact that angels higher up the hierarchy receive fewer but more universal intelligible species strongly suggests that their knowledge of things is still limited. Although they may know things-in-themselves, they do not know them as well as God knows them.
  • How could an angel, with such an excellent understanding of the nature of things, ever fall? (See Ia.q63).

Monday, 30 January 2012

Question 54 - The Knowledge of the Angels


Aquinas now turns to a series of questions (Ia.qq54-58) about how an angel’s intellect works and, in particular, its knowledge. Aquinas has placed the angels as purely spiritual creatures between man and God; infinite from below but finite from above. He has to sort out how the knowledge of the angels differs from the knowledge of God and from the knowledge of men. Although it may seem early to focus on the knowledge of the angels at this point and to spend so much effort on this subject, there is good reason. As the angels are purely spiritual creatures having form but no matter, the only powers that they have in their souls are those of intellect and will (as Aquinas points out in a5 of this question).

Why this Question Matters.

For this first question in the subsection about the knowledge of the angels, Aquinas asks about the angels’ knowledge or act of understanding in itself. Having placed the angels between God and men, Aquinas is concerned with differentiating their act of understanding and their power of understanding from these extremes. Therefore in building the contrary positions, in the objections, to those that he will argue for in his answers, Aquinas often uses analogies, either with the human intellectual faculties or with those of God. There’s a progression throughout the question from those things that might confuse the angels with God towards those where they might be confused with man.

The Thread of the Argument

A1: If one starts off by thinking about the human intellect, then Aristotle’s argument that the what-ness of the active intellect is identical with its action might seem to imply that an angel must be identical with its act of understanding. This is because an angel should be considered to be more sublime and more simple than the active intellect of the human soul and therefore cannot have more “structure” than this active intellect. However, the sed contra argues that the doing of a thing differs from what makes the thing what it is (its substance), more than the being of that thing differs from what makes it what it is. When we consider created entities, unlike God, we have to remember that their being differs from their substance and therefore their doing must differ from their substance.

Aquinas picks up from where the sed contra leaves off by pointing out that an action consists in the actualization of some power which is in potentiality. Therefore it is impossible for something that is not pure actuality to be identical with this actualization of a power alone. Only in God, who is pure actuality, is substance identical with being and with doing. In addition to this, Aquinas argues that were a creature to be identical with its act of understanding then this would give us a subsistent act of understanding. But there can only be one subsistent act of understanding (and this is God) in the same way that there can only be one subsistent whiteness.

In reply to the objections, Aquinas points out that the identification of the human active intellect with its action is simply not making an identification as far as substance is concerned but rather concerns concomitance; action and existence of the substance of the active intellect co-exist.

A2: If we can differentiate between the act of understanding of an angel and its substance, can we likewise differentiate between the former and its being? Aquinas recalls from the Metaphysics that there are two types of action: on the one hand there is the type of action that proceeds out of the agent and results in a patient being acted upon; on the other hand there is the type of action that does not proceed externally but which remains within the agent. (Aquinas suggests setting fire to something as an example of the first kind and sensing, understanding and willing as examples of the second kind.)

The first kind of action cannot possibly be the being of an agent; the being of an agent most definitely remains within the agent. However, this leaves open the second kind of action as a candidate for the being of an agent. But, curiously, such acts are in a sense too big to be the being of a creature. A creature is limited to being in a single genus and species whereas acts like understanding and willing have truth and the good as their objects and are therefore unlimited because truth and the good are transcendentals convertible with being itself. The acts of understanding and willing therefore receive their species from their objects rather than being fixed in a determinate genus and species. Even if we take the example of the act of sensing, it is still unlimited in a relative sense because it is related to all sensible objects. Only the being of God Himself is “big enough” to encompass all these objects and therefore it is only in Him that we can say that His act of understanding (or His act of willing) is His being.

A3: Aquinas has asked whether an angel’s act of understanding is identical with its substance or its being in the previous two articles and has rejected both identifications. He now turns his attention to the angel’s power to understand. This may seem a curious step, but it follows the pattern of previous questions which address the fact that what little we know about angels from the sources of revelation seems especially related to what they do, their powers to act. So here we ask whether the essence of an angel simply is its power to understand. This seems to be a reasonable question given the Christian tradition’s habit of thinking of angels as some sort of “pure intellect”.

Unsurprisingly, Aquinas rejects this position; it would make an angel (or any other created being) too much like God. Aquinas recalls that in created things, essence and being differ and essence is a potentiality to being; but the power to act is a potentiality to a particular being and this particular being is the act itself. As we have already seen that an angel’s being is not identical with his act of understanding, it cannot be the case that his potentiality to understand is his being either. Simply put, the potentiality to understanding is in potentiality to something less than the being of the angel. More generally, in a created thing the essence of the thing cannot be identical to the potentiality of the thing to do something. The idea of thinking of an angel in terms of intellect is a reasonable one given that an angel’s cognition is purely intellectual (Aquinas will develop this idea in the next few questions) but one must not make the mistake of identifying the power to know with what they are.

In the reply to the second objection, Aquinas makes an important metaphysical point. The objection suggested that since an angel is a simple form it cannot have any accidents; but if the angel’s power to understand is not identical with its essence then this power would have to be an accident. This contradiction is avoided because, although an angel is a simple form, it is not a simple form in which essence and existence coincide; the simple form remains in potentiality to its existence and this potentiality gives leeway for the existence of accidents. An angel can change as potentiality and actuality wax and wane and the particular position between potentiality and actuality can be regarded as accidental. For creatures that are composites of matter and form an individual is individuated by its matter and accidents can be associated with the individual. For an angel the accident pertains to its form and is therefore associated with its species (rather than any individual); but we recall from Ia.q50 that there is only one individual angel within each species!

A4: So far in this question, Aquinas has been concentrating on aspects of angels that might seem to make them a little too much like God; now he turns to an aspect of angels that differentiates them from men. Aquinas identifies in human beings a passive intellect and an active intellect. The passive intellect is that power within the intellect that is in potentiality to understanding and which comes to actuality in the understanding of things. On the other hand, the active intellect is that power of the intellect that renders intelligible the material things outside the soul that we come to understand. The basic idea is that the things outside ourselves that we come to understand are not in themselves intelligible to our intellects; there has to be a sort of abstraction from what is sensed into what we can comprehend. Once abstracted by the active intellect, the passive intellect receives what are called intelligible species and is moved from potentiality to understand to actually understanding. Aquinas will develop these ideas in much more detail in Ia. q79 and beyond.

Here Aquinas asks whether the same is true in angels: do they have both an active and a passive power within their intellects? His answer is swift and opaque: no, because the way they understand is simply different from the way we understand and the there is no need to posit the powers of “making intelligible” or of a potential to know being made actual in angels. Aquinas will consider the question of what the angels know and how they know it in the next few questions; but for now we will simply have to make do with the assertion that they do not use sense organs to gather information about sensible objects, nor do they have to interpret and organize this information in the same way that we do.

A5: The concentration on the intellectual powers of the angels to the exclusion of any consideration of imagination, sensing or memory (or any other human powers of cognition) in this question will have already prepared us for the coup-de-grace of this article: angels’ understanding is a purely intellectual understanding. The reason for this is very simple: as angels do not have material bodies, the only powers they have in their souls are those of the intellect and the will.

The objections point out a number of examples from the tradition where the Fathers talk as though angels have other cognitive powers, so in the replies to the objections Aquinas gives an account of how these are to be correctly interpreted.

Handy Concepts

  • Angels are simple pure forms, but they are still composites of actuality and potentiality. This observation rules out attempts to identify what an angel is or its being with its act of knowledge or with its power to have knowledge.
  • Angelic knowledge is, in many senses, quite unlike human knowledge and the angelic intellect has far less structure than that of humans. Aquinas will elaborate on these aspects of the angels over the coming questions.
  • The identification of the powers of the passive and active intellects within the human intellect might be seen as a corrective to the later excesses of idealism.