Chapter IV -- 8
St Thomas Aquinas then turns to the intellectual powers of the soul, the ones that only man has among the animals.
St Thomas raises the very important question whether the intellectual power of the soul is a power of the soul or the very essence of the soul. We have already, in Section 13 of Chapter III, discussed the connection between mind (nous) and soul (psuche) both in St Gregory of Nyssa and in Evagrius Pontikos. There we concluded, following St Gregory of Nyssa, that the mind (nous) was the essence of the soul. This is a Platonic conception. St Augustine seems to have had much the same view. However, here we see that St Thomas rejects this view: for St Thomas, the intellect (Latin: intellectus; = Greek: dianoia) is a power of the soul, not its essence. It should be understood, however, that although St Thomas uses the word ‘intellect’ here, he means it as a synonym for ‘mind’: it is not as if he is saying that the intellect is a power of the soul and the mind its essence.
It should be recalled that St Thomas Aquinas, St Gregory of Nyssa and St Augustine have roughly the same psychology as concerns the three parts of the human soul, what in the works of St Gregory of Nyssa and Evagrius Pontikos we learned to call the mind (nous), the temper (thumos) and the desire (epithumia). Moreover, we learned from Evagrius Pontikos to call the temper (thumos) and the desire (epithumia) taken together, the passionate part of the soul.
Of course, this tripartite division of the soul in man is ultimately due to Plato, and, most certainly, St Thomas received it from Plato by way of the Roman Catholic tradition of anthropology which derives from St Augustine, and then modified it according to his interpretation of Aristotle.
Aristotle himself maintains the basic outline of the tripartite soul that he himself received from his master, adding to it, however.
What is in issue, then, is St Thomas’ interpretation of this ultimately Platonic model of the tripartite soul. For we see that St Thomas is rejecting the Platonic notion that the mind (nous) is the essence of the soul. Following Aristotle, he makes it a power of the soul.
St Thomas establishes that the intellect, here taken as a whole, is a passive power of the soul. In regard to the whole intellect, St Thomas means ‘passive’ in the sense that the intellect is passing from potency (Latin: potentia; = Greek: dunamis) to act (Latin: actus; = Greek: energeia) in regard to universal being (ens). This is a very difficult part of Thomist metaphysics, but let us see if we can convey the central idea simply and clearly:
There is one intellect that is in a state of pure act [let us say, following the corresponding Greek, pure actualization or pure actuality or pure operation—that is, pure act without potency or potentiality of any kind] with regard to universal being (ens): that is the Divine Intellect, which is the essence of God, in which every being pre-exists originally and virtually, as in its First Cause.
Let us interrupt here.
The reader may recall that St Gregory of Nyssa posited in On the Making of Man that all concrete, individual men pre-existed in the foreknowledge of God, even though each concrete, individual man’s soul actually came into being at the instant of his bodily conception. The same principle is involved here.
Moreover, here there is also involved the concept of the reasons (logoi) of created beings in the Mind of God. We shall occupy ourselves in Volume II with these reasons (logoi) as they are understood by Evagrius Pontikos. In the Neoplatonic tradition, these reasons (logoi) are the essences of created things, which essences exist eternally in the Divine Intellect before the objects come to be whose essences they are. It should be recalled that in Classical philosophy what the intellect understands is the essence of the thing, and that that essence is here being identified with the thing’s reason (logos) in the Mind of God. This concept of the essences, the reasons (logoi), in the Mind of God, due to the Neoplatonist, Plotinus, and based ultimately on the forms of Plato, is to be found in St Augustine.
Let us continue with St Thomas where we left off:
For this reason, the Divine Intellect is not in potency but is pure act. However, no created intellect can have itself in act in respect of the whole of universal being (ens) [i.e. can, in a single act of knowing, know the whole of universal being], since it would then be necessary that it be infinite being. Therefore every created intellect, through the very fact that it is created, is not the act of [knowing] all the intelligibles, but is constructed in relation to those very intelligibles, as potency (potentia) proceeding to act (actus).…
Therefore the angelic intellect is always in act in respect of those intelligibles which are proper to it, on account of the angel’s closeness to the First [Divine] Intellect, which is pure act…
The human intellect, however, which is lowest in the order of the intellects and the furthest away from the perfection of the Divine Intellect, is in potency [proceeding to act] in respect of intelligibles…
For in St Thomas’ system the Divine Intellect is not only the essence of God, but that essence of God is identical with the being of God, which itself is pure act. Moreover all created beings receive their being by participation in the being of God, and that in a highly articulated hierarchy of perfections of being.
First are the highest angels; then the lower angels, illumined by the higher; then man, last among the created intellects, the least of the created intellects.
But there are not just nine kinds of angels in St Thomas’ system: the nine kinds, due to St Dionysios the Areopagite, are merely the broadest classes of angels: the actual hierarchy is much more complex.
This system is important to understand for the sake of St Thomas’ anthropology, for while St Thomas agrees that man is created in the image of God, in his view, the angels are created more in the image of God. In St Thomas, there is a different orientation from the anthropocentric notion that we find for example in St Maximos the Confessor, that man is the crown of creation who links together both the intelligible and the material creations: St Thomas posits a very complex mosaic, let us say, of being and places man in an inferior part of that mosaic as a very small part of it, as the least perfect image of God among the intellectual beings. It is tempting to see here a reflection of the mediæval community as a highly stratified society with very rigid class boundaries, in which the individual was a very small part of a highly defined and articulated whole, quite the opposite of our own modern culture, which is on the one hand a mass culture and on the other hand an urban culture centred on the individual taken as a free-moving atom.
However, St Thomas’ notion that man’s ability to intuit the first principles of reason such as the law of the excluded middle brings man to the border of the angelic world seems a faint echo of a doctrine of man as a connecting link between the earthly and the spiritual realms—although, clearly, in St Thomas’ view man is merely a small part of a grand mosaic: St Thomas is not anthropocentric in the same sense as Greek Fathers such as St Maximos.
Moreover, although St Augustine himself taught a doctrine of the degrees of participation of created being in God, he is more anthropocentric than St Thomas Aquinas. His orientation is more similar to that of St Maximos. This might indicate that one reason the late Classical Age of Rome is both similar to and relevant to our own age is that it was an urban culture centred on the free-moving individual. That this might be so can be seen in St Augustine’s emphasis on the psychology of the individual, on the actual experience by the individual of his own consciousness as the foundation of an experiential proof for the existence of God: St Augustine has stripped away the whole apparatus of cultural determinants of belief in order to begin with the individual’s consciousness of thinking. This accords with a social setting in which the individual is no longer determined by social and cultural factors, but only by his conscious personal existential choices. This is similar to the modern urban West. It is very far removed from the world of St Thomas.
To return to St Thomas, we here see very clearly both the central role in St Thomas’ thinking of the dual notions of potentiality (potentia) and actualization (actus), and the importance of his notion that God is pure being equal to pure essence equal to pure intellect equal to pure act and so on. This treatment of God as pure being and so on distinguishes St Thomas from St Maximos the Confessor, that other interpreter of St Dionysios the Areopagite, and allows St Thomas to adopt a ‘positivist’ approach to God that is absent in the Greek Patristic tradition. It allows him to manipulate the concept of ‘being’ in a context of philosophical metaphysics in such a way as to create a vast system based on being, one that handles all the issues of philosophy and theology ‘positively’: St Thomas’ system provides you with all the answers to all the questions you might wish to raise concerning the being and existence both of God and of his creatures.
 ST Ia, 79.
 ST Ia, 79, 1.
 ST Ia, 79, 2.
 We are quoting ST Ia, 79, 2; see also Gilson E p. 234.
 This similarity of the doctrines of St Dionysios the Areopagite and St Augustine should be taken to reflect the Neoplatonic roots of both authors.