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.
- 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.