Chapter IV -- 13
We now wish to discuss
Second, as we shall see in Volumes II and III, Evagrius Pontikos and St Hesychios each discuss a model of temptation and sin as a part of their ascetical doctrines. In fact, St Hesychios’ own model of temptation and sin is an amalgam of the models of temptation and sin of Evagrius Pontikos and of St Mark the Ascetic. There are certain similarities between St Thomas’ model of human action and the model of human action presupposed in the models of temptation and sin of Evagrius Pontikos, St Mark the Ascetic and St Hesychios. A consideration of St Thomas’ theory of human action will help us better to understand the issues involved.
Third, in Chapter I, above, we discussed projects in artificial intelligence which are based on the presupposition that the human mind is nothing more than a hierarchy of algorithms. St Thomas’ analysis of human action can be seen as an early attempt to construct a formal model of human action, an attempt that is very similar to modern attempts to resolve the human mind into algorithms. We think that a modern researcher into artificial intelligence would find a study of St Thomas’ theory of human action useful in the design of robots. Moreover, glances at this dimension of St Thomas’ theory of action will help us to grasp more clearly some formal aspects of his theory.
St Thomas’ theory of human action, the preliminary to his own analysis of human moral action, is very complex and we can only delineate its broad outlines. It is remarkable for its rationalism and for its treatment of the human will as an intellectual appetite subordinate to the reason. St Thomas places his theory of action in the context of his doctrine that the human will is an appetite that by nature necessarily tends to the good, above all to the Beatific Vision. It should be remarked that St Thomas’ model in the Summa Theologiae, while certainly reflecting his own mature thought, was disputed after St Thomas’ death by other Scholastics.
St Thomas first establishes that it is proper to man to do all things for an end. His asserts that the only actions that are proper to or characteristic of man are actions of which man is master, and that man is master of his actions only by means of his reason and his will. Therefore, he says, following Aristotle, the only actions proper to a man are those which proceed from a will which is exercised after due deliberation.
This is a very basic move on St Thomas’ part which sets the stage for his analysis of human action: by asserting that what is properly human in an action is to act rationally for an end, he has enabled himself to conduct an extremely detailed analysis of human action within a very rationalistic and intellectualistic framework. For having isolated acting rationally for an end as the essentially human aspect of an action, he can proceed to analyse ends and means, and the interplay of the reason and the will in the choice and execution of the means to the end. Although St Thomas is following Aristotle, his analysis is much more rationalistic.
St Thomas proceeds to establish that human actions are specified by their end. The end of an action is the goal or purpose of the man who does the action.
St Thomas establishes that human life has a final end. This of course is beatitude, the Beatific Vision, the vision of the essence of God, the direct knowledge of God, attainable in St Thomas’ theology only upon death. This doctrine of the tendency of all men to beatitude St Thomas has derived from St Augustine.
It is necessary for us to consider the source of St Augustine’s own doctrine in order for us to be able to assess as we proceed the transformation that has taken place at St Thomas’ hands of the Augustinian concept of beatitude. It seems to us that the source of St Augustine’s doctrine of beatitude is Plotinus’ Enneads, which St Augustine read in the Latin translation of Marie Victorinus. For we see in the Enneads the central role of eudaimonia in Plotinus’ system. But this eudaimonia (literally: ‘happiness’) is clearly defined by Plotinus to be union in eternity (i.e. beyond time but possibly in this life; not necessarily after death) with the One, which is elsewhere called by Plotinus, God. This union is understood by Plotinus in what today would be called ‘intellectualistic’ (although certainly mystical and, in our own terminology, ‘intuitive’) terms. Moreover, although the person who experiences this mystical union in eternity with the One may return to earth (i.e. to time and to the world of sense-perception, as Plotinus surely did from his own repeated experiences of this union with the One), he remains eudaimon: the event confers eudaimonia on him. In ordinary language, we would say: ‘He has been enlightened.’
This doctrine of Neoplatonism St Augustine has transposed into the context of the Christian Gospel, and he has reserved the fullness of it for the next life, surely a Scriptural position. Now the atmosphere of Plotinus is completely different from the strict rationalism of St Thomas as St Thomas applies that rationalism to Aristotelian metaphysics: Plotinus is a pagan mystic. Now St Augustine is himself a Christian mystic, but he retains the flexibility of Neoplatonism. Although St Thomas is also a Christian, with his rationalism and intellectualism (in a different sense from the ‘intellectualistic’ mysticism of Plotinus), with his rationalistic Aristotelianism, he has departed completely from the thought-world of Plotinus and St Augustine: he retains, as we have seen, certain concepts of St Augustine, derived ultimately from Plotinus, as he must, but he is really moving in a different thought-world. This creates a rigidity in his handling of these concepts, as we have already seen and shall see below.
Much of St Augustine’s own doctrine, especially his own psychology of the intelligence or superior reason, of the divine light, of the nature of ‘understanding’ become noticeably more comprehensible when seen in the light of Plotinus. For example, the intelligence or superior reason is seen to be the capacity of the human soul to know God intuitively; the divine light is seen to be a Christian adaptation of the Plotinian idea of the Mind (Nous) as immanent in the soul; ‘understanding’ becomes not rational comprehension of propositions via ratiocination, but the intuitive grasp by the soul of God in mystical union, so that St Augustine’s ‘faith seeking understanding’ becomes a process of moving from belief in God to mystical union with God, where the initial faith or belief is seen to be the foundation of, and stepping-stone to, the mystical union with God, which itself takes place in fullness in the next life.
To continue with St Thomas, St Thomas establishes that human life has only one final end. That of course is the Beatific Vision.
St Thomas establishes that everything that a man desires he desires in view of his final end. This is important for an understanding of how St Thomas ties his doctrine that all men tend to the final end, beatitude, to his theory of concrete human actions. St Thomas says this:
It is necessary that a man desire (appetat) all that he desires on account of the final end, and this appears by a double reason. First, since whatever a man desires, he desires under the aspect (ratione) of the good. For if something is not desired under the aspect of the good, which is the final end, it is necessary that it be desired as tending to the perfect good, since the beginning of something is always ordered towards its consummation, just as is shown both in those things which are made by nature and in those things which are made by art; and thus the beginning of every perfection is ordered in the consummated perfection, which itself is on account of the final end. Second, since in moving the desire the final end disposes itself in the same manner as the first mover disposes itself in other movements. However, it is manifest that secondary causes, when they move, do not move except insofar as they are moved by the first mover. Whence secondary things that are desirable do not move the appetite except by an ordering towards the first thing which is desirable, which is the final end.
St Thomas is giving two reasons why it is on account of the final end that a man desires all the things that he desires. His first reason is that whatever a man desires, he desires because it is good. But the good is the final end. Moreover, if something is desired but not because it is good, it is desired because it tends to the final good. Thus, the beginning of a perfection is ordered in relation to the perfection as that perfection will be when it is consummated, and that consummated perfection is on account of the final end. St Thomas’ second reason is that the final end, beatitude, has the same relation in moving the desire, or appetite, that the first mover has in causing other movements. But secondary causes move things only insofar as they are moved by the first mover. Therefore, secondary objects of desire move the appetite only because of a relation they have to the final end.
This is an important doctrine, although it is not clear how it is to be integrated into the rest of St Thomas’ theory of action. For St Thomas does not suggest that a man actually deliberates consciously about the extent to which a possible end contributes to his beatitude—though he certainly implies that a prudent man will so deliberate, so as to attain to the Beatific Vision when he dies. For example, it occurs to me that it might be good to go for a walk. St Thomas does not suggest that before deciding to go for a walk I consciously deliberate whether going for a walk might or might not contribute to my attainment of the Beatific Vision. However, he certainly implies that if I am prudent I will conduct all my affairs with a view to my attainment to the Beatific Vision. Moreover, there is no doctrine in St Thomas of unconscious motivations: it cannot be thought that St Thomas means that unconsciously I evaluate my every action with a view to my possible beatitude. However, he does mean, within the Aristotelian doctrine of final causes, that any end I choose is necessarily ordered to the final end, beatitude, in the same way that a secondary mover is put into motion by the first mover. This means that an object of desire, an end, can be an end only insofar as it bears some intrinsic relation to the final end, beatitude, as to the final cause, and that that relation is a relation of goodness. Moreover, St Thomas’ doctrine is that the will, a rational desire, can only desire in view of the final end. This is a doctrine of the nature of the will as desire: it can only move towards the Beatific Vision. However, that doctrine is later qualified: God moves the will, a desire, towards the good, but before death it is the intellect that presents to the will its good. Secondary goods, those other than the Beatific Vision, can be good in one respect and ‘not good’ in another, so the will is not bound to desire them or not to desire them: it has a freedom to move or not to move towards a secondary good.
To what extent is the problem of the metaphysical nature of the will in St Thomas Aquinas as a necessary desire or tendency towards the good or beatitude or the Beatific Vision, due to the fact that St Thomas has injected the essentially psychological analysis of St Augustine that all men seek after beatitude into a severely logical or rationalistic version of Aristotelian philosophy; that is, that he has injected the psychological insight of St Augustine into metaphysics, freezing it in a highly articulated logical system based on being and not on the psychology of man, a system focused on the nature of a part of the soul called the will, which must obey, along with another part of the soul called the reason, certain metaphysical rules?
St Thomas establishes that all men are in agreement in their desire for their final end, beatitude. This doctrine, just like the one in the preceding article, you either accept or reject. For it is expressed throughout St Thomas’ theory of action in such a way as to be tautologically true. Moreover, it has to be seen in the light of St Thomas’ doctrine that the will is intrinsically a hunger or thirst after the Beatific Vision. Once the reader accepts that definition, then all else follows. For how would one prove that every man had a hunger after beatitude? How would one disprove it? A man’s actions can always be interpreted in such a way that it might be said that the man hungered after beatitude in a mistaken way. And that is what St Thomas does. In St Augustine, these propositions arise from a psychological, not metaphysical, analysis, and in that setting they seem profound insights into human psychology. In the setting of Aristotelian metaphysics, they seem both rigid and disputable.
St Thomas establishes that only man among creatures has beatitude as his final end. Since the animals and the lower creatures lack reason, they lack will, and they therefore cannot pursue rational ends such as the Beatific Vision. The angels, however, already enjoy the Beatific Vision.
This series of propositions is very important for it lays down the presuppositions of St Thomas’ theory of action.
 To an extent we have drawn on A. Donagan’s article ‘Thomas Aquinas on human action’ in the Cambridge History of Later Medieval Philosophy (Medieval pp. 642–54).
 ST Ia IIae, 1, 1.
 ST Ia IIae, 1, 3.
 ST Ia IIae, 1, 4.
 Enneads I, 4: Plotinus I, 4 .
 ST Ia IIae, 1, 5.
 ST Ia IIae, 1, 6.
 ST Ia IIae, 1, 7.
 ST Ia IIae, 1, 8.