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 something, the senses present phantasms to the intellect, the raw materials of what they detect. (These phantasms might be thought of as what are termed qualia in modern philosophy.) So vision presents patches of coloured light and shade, hearing presents sounds, and so forth. If we take the example of seeing a vase, the sense of sight presents visible phantasms which the active intellect then organizes into what is termed an intelligible species; this is a form present in the mind by way of which the mind understands the original object of perception. The intelligible species is a sort of image of what is perceived in the mind; it is not the thing that is perceived but it is the thing by which the original object is perceived. The other faculties of the mind go to work on the intelligible species, so to speak, 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 though 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 though 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.
- 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).