Aristotle’s Concept of God
Stanley Sfekas, Ph.D.

Aristotle conceived of God as outside of the world, as the final cause of all motion in Nature, as Prime Mover and Unmoved Mover of the universe. He was the crowning objective of all dynamic development in the cosmos from matter to form and from potentiality to actuality. He stood outside the Great Chain of Being yet was the source of all motion and development. Aristotle did not attribute mercy, love, sympathy and providence to God, but rather eternal self-contemplation. Yet Aquinas and the medieval theologians achieved a synthesis of Aristotle’s God and Christianity. For Aristotle, metaphysics ultimately culminates in theology
God serves two roles in Aristotle’s philosophy. He is the source of motion and change in the universe, and He stands at the pinnacle of the Great Chain of Being by providing an example of pure form existing without any relation to matter. Aristotle’s theology is set out in books VII and VIII of the Physics and Book XII of the Metaphysics. It can be summarized in the answer to two questions: (1) Why must we postulate the existence of God? And (2) What can we know about God?
In answer to question (1), Aristotle develops one argument, the argument from the existence of change or motion. His statement is very complex, but its main outlines can be indicated as follows: (a) There exists an eternal circular motion, namely the movement of the sphere of the fixed stars. (b) Everything that is moved is moved by something else. (c) Therefore, there must be either an infinite series of causes or a cause of motion that is itself unmoved. An infinite series of motions is impossible. Therefore, (e) there is an unmoved cause of motion, and this is God. This argument is not taken seriously today since most of its premises have been rejected by modern science. The claim that there exists an eternal circular motion is incompatible with the Second Law of thermodynamics. The second premise that everything that is moved is moved by something else is incompatible with Newton’s first law of motion. And if this is false then we do not have to accept premise (c) and its disjunction between an infinite series and an unmoved mover. Aristotle gives no satisfactory proof of (d) that an infinite series is impossible. Nonetheless, this argument has had a long history. It was canonized by Aquinas as one of his “five ways” to God, and is still seriously propounded in neo-scholastic textbooks of natural theology.

Aristotle’s reply to the second question, “what can we know about God?” runs as follows: Since God is an unmoved mover, he must be changeless. He cannot therefore be composed like other substances of actuality and potentiality. He must accordingly be all form, all actuality, and so completely immaterial. He moves the outermost sphere of the fixed stars and this motion is transmitted to the inner spheres by ordinary mechanical processes. But God himself does not move the outer heaven mechanically. Indeed, He could not do so, since He is immaterial and not in space. Instead, He moves it in a non-physical way—by being an object of attraction or desire. God is thus efficient cause by being a final cause. His own activity, being that of a purely immaterial being, must be an activity of thought that has itself as an object. Any lesser object would be a degradation of His divinity, and a changeable object of thought would entail a change in the thinker. “Its thinking,” Aristotle concludes enigmatically, “is thinking on thinking.” (Noesis noeseos). God is absolute self-consciousness.

In determining the content of divine thought, Aristotle uses a form of argumentation known in metaphysics as the doctrine of metaphysical perfection. God is conceived as a perfect being, and Aristotle simply carries the doctrine of God’s perfection to its logical conclusion. The perfect being can only think perfect thoughts. To think anything less than perfect would be imperfect, and a contradiction. Therefore, the only content of thought that would be worthy of being thought by a perfect divinity would be itself. Therefore God contemplates himself. If he were to contemplate anything other than himself, he would be contemplating the less than perfect. This suggests that god would not be contemplating the world. Aquinas argues that God in contemplating himself has indirect knowledge of the world.

Sir David Ross, the Oxford translator of Aristotle states that Aquinas’ solution is promising but that it is not the way of Aristotle. If so, then it is understandable why Aristotle’s concept of God has been criticized as cold and inhuman. On this view, Aristotle’s god does not inspire, even though his activity, contemplation, is one that humans should imitate if they are to lead the best and happiest life. The idea of a God remote from the world, in no sense its creator, and indeed knowing nothing about it, may well seem repugnant to those brought up with Christian beliefs about god. And yet Aristotle’s doctrine is in the main the consequence of carrying the principle of god’s perfection to its logical conclusion, and it has always proved difficult for other, less inhuman theologies to explain the relation between a perfect God and an imperfect world. Moreover, while Aristotle’s God is not affected by the universe, as the final cause it is the principle on which the universe depends and to which it aspires. In Aristotle’s words, “On such a principle the heavens and nature depend.” And here Aristotle asks whether the good belongs to the universe as something separate from it—as we might say, transcendentally—or in the arrangement of its parts—as we might say, immanently—and he answers that it does so in both ways, drawing a comparison with an army whose good lies partly in its arrangement and order, but also and more especially in the general on whom the order in the army depends. If his God is remote from the world, Aristotle believes nevertheless that that the whole of nature seeks and desires the good: final causes are at work throughout nature, and God is the ultimate final cause.

It is interesting to follow the reasoning that led him to affirm the existence of the immaterial and perfect being that he called God. That reasoning provided a model for later thinkers in their efforts to prove the existence of God—not Aristotle’s God, but the God of Genesis, the God who created the world out of nothing, creation ex nihilo.

The conception of God as Prime Mover and God as Creator are alike in three respects: the immateriality, immutability, and perfection of the Divine Being. But Aristotle’s Prime Mover only accounts for the eternity of the universe and its everlasting motion. It was the need to explain that which led Aristotle to develop his theory of the motion of the heavenly bodies and his concept of the Prime Mover as the final cause of their movements.

Aristotle did not think it necessary to explain the existence of the universe. Being eternal, it never came into existence, and so, in his view, it did not need an efficient cause that brought it into being—a cause that operated like a human maker who produces a work of art. We normally speak of the human being who makes something as creative. However, the human creator always has the materials of nature to work on. He does not make something out of nothing. He is, therefore, not creative in the way that God is thought to be creative.

The conception of God as Creator arose from the need to explain the existence of the universe, just as the conception of God as the Prime Mover arose in Aristotle’s mind from the need to explain the eternity of the universe and its everlasting motion. It is difficult to determine whether the conception of God as creator would have arisen in the minds of later thinkers in the West had it not been for the opening sentence of Genesis, which reads: “In the beginning God created the heavens and the earth.” This is regarded as divinely revealed truth by the three major religions of the West—Christianity, Judaism, and Islam.
It would be both natural and reasonable to ask whether Aristotle would have accepted or rejected what is asserted by that sentence. Since he thought the universe to be eternal, would he not have denied that the universe had a beginning? And denying that, would he not also have rejected the notion of a God who created it.

If to create is to cause something that does not exist to come into existence, (comparable to what the human artist does in producing a work of art), then a world that has no beginning does not need a creator. But even a world that has no beginning may need a cause for its continued existence if its existence is not necessary. Something that does not necessarily exist, in Aristotle’s view, may or may not exist. If the world does not exist necessarily, it may cease to exist. What then causes a world that may cease to exist everlastingly in existence?

Aristotle had reasoned his way to the conclusion that a cause was needed to keep the universe everlastingly in motion. By parity of reasoning a cause would be needed to keep the universe everlastingly in existence, a sustaining cause, a cause in esse as the medievals put it. By a slight shift in the meaning of the word ‘creator’ in the sense of ‘sustainer’,
In one sense of the word, to create is to cause something that does not exist to come into existence. In another sense of the word, perhaps a more subtle sense, to create is to cause the existence of that which may or may not exist, without regard to its coming into existence. It is in the latter more subtle sense that Aristotle might hve conceived God as both Prime mover and Creator.
Another objection to Aristotle’s concept of God is that the Prime Mover is not a God of providence and of love. It took the genius of Aquinas to argue that Aristotle’s God is implicitly a God of providence and love. Aquinas reasons that God is self-subsisting existence, ipse esse subsistens. From this he deduces other properties which must belong to God. Aquinas notes that ipse esse subsistens, and actus purus and prime mover are metaphysical names of God and are applicable to one and the same substance. Thomas proves the infinitude and perfection of God from the notion of self-subsistence. God’s eternity is proved from the same notion and also by way of immutability, which is proved by God’s being simple, infinite, and actus purus, pure actuality: there can be no change or movement in God since there are no unactualized potentialities in him. That god is not body—i.e., is immaterial—is proved as part of his simplicity. His immateriality can be said to be a consequence of his being pure act, i.e., without matter.
Now from these metaphysical properties of God (God as infinite, immaterial, pure act, etc.), these Aristotelian properties, Thomas passes on to the properties of the Christian God as he is revealed in the scriptures. For instance, the Christian God is there supposed to be alive, omniscient, and loving. And now the presence in God of perfect knowledge is proved from his immateriality.
The order in which certain other properties are proved is in itself highly interesting. That God is living is proved from his intelligence, truly in the spirit of Aristotle. Furthermore, the presence in God of perfect knowledge is used to show that God is also the cause of things. It is manifest, Thomas says, that God causes things to be by his intellect. For his being, esse, is to understand, intelligere; therefore it is necessary that his knowledge is the cause of things. He adds, though, according as he has a will which joins in. I will comment on this additional clause in a moment. The idea behind this argument is this: Anybody who wants to make or produce something must have an idea or a previous knowledge of what he wants to produce. As Thomas puts it: “The knowledge of God is related to all created things as the knowledge of an artisan is related to the artifact which he produces.”

The additional clause stipulated that the cooperation of the divine will is also necessary for the act of creative causation. This might make one think that the intellectualist view of God as prime cause is tempered by an element of voluntarism. But a closer reading shows that this is not so. For in a subsequent question Thomas explicitly says that the divine will is a consequence of the divine intellect. “There is will in God just as there is intellect. For the presence of will follows upon the presence of intellect. Therefore there is will in any being that has intellect.” This statement is a very clear expression of a theologico-philosophical position sometimes designated as “the primacy of the intellect over the will.” Whether the will or the intellect should be regarded as the lord and governor of the soul was one of the critical issues debated in medieval philosophy.

The derivation of the divine will from the divine intellect is one of the decisive steps in Thomas’ reasoning concerning the nature and properties of God. it is hardly surprising now to find that God’s love is viewed as a consequence of his will. Thomas asks whether there is love (amor) in God, and he answers:” In whatever being there is will or appetite, there must also be love. It has been shown that there is will in God, therefore is necessary to suppose that there is love also.”

Thus, in sum, God’s life, will, and love appear as necessarily following or flowing from his intellect. The pride of place accorded to the intellect in the Thomist description of the nature of God is considered by critics a crucial move in the history of theology and it exfoliates what is implicit in Aristotle’s concept. Thomas deduces the properties of the Christian God, providence and love, from Aristotle’s Prime Mover as Noesis noeseos.

Is the God of Aristotle a personal God? Aristotle sometimes speaks of the prime mover as o theos. Aristotle may not have spoken of the Prime Mover as being personal, and certainly the ascription of anthropomorphic personality would be very far indeed from his thoughts, but since the Prime Mover is Intelligence or Thought, it follows that he is personal in the philosophic sense. The Aristotelian God may not be personal secundum nomen, but he is personal secundum rem. It should be noted here that there is no indication that Aristotle ever thought of the Prime Mover as an object of worship, still less as a Being to whom prayers may be profitably addressed. It requires the further deductions of St. Thomas Aquinas to give us the God of providence and of love.