Chapter 003 - The Simplicity of God

God is not corporeal; first, because movement is not possible to a body except by an external agent – God is the First Cause of motion, Himself being immovable, as was shown above; secondly, a body is a potentiality {in potentia) because, as it is continuous, it is divisible indefinitely, whereas God is a Being in Act and Pure Act; thirdly, God is the noblest of all Beings in Act, and, therefore, cannot be corporeal, a body being either living or not living, and a living body is nobler than a not living body; but a living body does not live as such, otherwise every body would live, and so it must live by another, which is the soul. That which gives life to the body is nobler than the body. It is, therefore, impossible that God should be corporeal.

God is not composed of matter and form. Matter is of itself a potentiality. God is True Actuality, having no potentiality. Further, every created being is good and perfect by virtue of its form and by participation, as matter participates form; but as God is the first and highest Good, He is not Good by participation, but by His own Essence; therefore He is not composite. It is clear also, from His being the First Efficient Cause, and, therefore, the First Cause and acting of Himself, and Form by His own Essence, why He is not composed of matter and form. God is identified with His Essence or Nature, whereas in single forms which are their own individuality the subject is the same as the nature; and, therefore, God is His own Deity and His own Life, and all else that can be predicated of Him. In things composed of matter and form nature differs from the subject, because the nature or essence comprehends in itself only what falls under the definition of Species, and so it does not comprehend the individualizing matter, and thereby it is distinguished from the subject. So God is not only His own Essence, but His own Existence; for whatever is in anything besides its essence must be caused either by the essence or by some external agent; but it cannot be by the essence alone, for to be its own cause of being is beyond any being. If this is caused by an external agent, it must be as regards anything that has existence and essence distinct, that it should have a cause other than itself; but with God that cannot be, for He is, we have seen, the First Efficient Cause. Further, existence when distinct from essence is related to it as act to potentiality; but God is Pure Act with no potentiality, and, therefore, He is identified with His Essence; this is evident likewise from the fact that He is the First Being, and, therefore, must Be. If His Existence and Essence were not the same, He would Be by participation, and thus He would not be the First Being; which is absurd to say of God.

Neither is God, properly speaking, in any genus. Species is made of genus and difference; and that from which difference comes stands towards that which makes the genus as the actual to the potential (thus the rational may be compared to the sensitive, as the actual to the potential, and so on); but since in God the potential cannot be added to His Actuality, it cannot be that He should be as a species in a genus. Moreover, if God were in a genus, it must be that of Being, for genus signifies the essence of a thing, as when we predicate of a thing that it is such; but Being cannot be a genus, as Aristotle says, because every genus has differences external to its essence, whereas no difference can be external to simple being. Therefore, God is not in a genus, for outside of Being there is only not-Being, which cannot be the difference among beings. Besides, all the members of one genus have those things in common which constitute the genus in Its essence (of which it may be predicated that it is such), but they differ in their being; thus the being of a man is not the same as that of a horse, nor is the being of one man the same as another’s. There is a necessary difference, therefore, between being (or existence) and essence in things which are in a genus; whereas the contrary has been proved in God, and, therefore, He is not in a genus. Neither does He belong to a genus by reduction to first principles, for whatever belongs to a genus by reduction does not extend beyond it; whereas God is the First Principle of all Being, and hence He cannot be contained as the first principle in any particular genus.

Nor can there be any accident in God. The subject is to the accident as the potential is to the actual, and God being Pure Actuality, the potential has no place in Him. Then, as God is His own Existence, there can be nothing added to His Nature; just as heat has only heat, although a thing which is hot may have something external added to the heat, such as whiteness. Thirdly, whatever exists of itself is prior to that which is accidental. Hence, as God is the First Being, there cannot be in Him anything accidental.

God is, therefore, wholly Simple, for in Him there is no composition nor quantitative parts, neither is His Nature distinct from His Subject. He is wholly Simple likewise because what is composite comes after its component parts, and depends upon them; whereas God is the First Being. Moreover, a thing composite has a cause for its unity; but God has no cause, being Himself the First Efficient Cause. Also, in everything which is composite there is potentiality and actuality, which have no place in God. Finally, everything which is composite is a whole separate from its parts, whether like or unlike, which can in no way be said of God, Who is His own Form, or rather His own Being, and, therefore, is wholly Simple.

Neither does God enter into the composition of any other things, as some have erroneously thought and said that He was the soul of the first heavens, or the formal principle of all things, or primal matter {materia prima), for God is the First Efficient Cause, and such cause is numerically distinct from the form of the effect, and can only agree with it in species, as in the case of man generating a man. Matter does not agree with its efficient cause either numerically or specifically, for it is in potentia,, and the latter is in actu. God, as the First Cause, is the highest, and acts by His own power; and so He is not a part of anything else. Nor can any part of a composite thing be the absolute first among beings, as God is; not matter nor form, which are the principles of anything composite; for matter, which is potentiality, is simply posterior to actuality, and form, which is part likewise, is participated form which comes after that which is Form by Essence. Therefore God does not enter into composition at all.