Article 1 — Whether God is simple

The first point of inquiry is whether God is simple. (Parallel texts: ST I.3.7; SCG I.16, 18; In I Sent. 8.4.1; Compendium theologiae, ch. 9; Commentary on the Book of Causes, lect. 21.)

Obj. 1: And it seems that he is not. For from one simple thing, only one thing can naturally proceed, for the same thing always produces the same thing, according to the Philosopher. (Aristotle, On Generation and Corruption 2.10, 336a15–b1.) But many things come from God. Therefore, he is not simple.

Obj. 2: If a simple thing is reached, the whole of it is reached. Now, God is reached by the blessed; for, as Augustine says: to reach God with the mind is great blessedness. (Augustine, On Seeing God 6.18, 23.52–53 (PL 33:603–4, 621).) If, then, God is simple, he is wholly reached by the blessed. Now, what is wholly reached is comprehended. Therefore, God is comprehended by the blessed, which is impossible. Therefore, God is not simple.

Obj. 3: The same thing cannot be several kinds of cause. Now, God stands in the account of several kinds of cause, as is clear from Metaphysics 11. (Aristotle, Metaphysics 11.10, 1067a33–37; cf. 12.4–5, 1070b22–1071b2; 12.10, 1075a11–1076a4.) Therefore, there must be various things in him; and consequently, he is composite.

Obj. 4: Whatsoever contains one thing in addition to another is composite. Now, in God, there is one thing besides another, namely, property and essence. Therefore, there is composition in God.

Obj. 5: It will be replied that the property is the same as the essence.

On the contrary, affirmation and negation are not true of the same thing. Now, the divine essence is common to the three persons, whereas a property is incommunicable. Therefore, the property and the essence are not the same thing.

Obj. 6: A thing is composite if different categories are predicated of it. Now, substance and relation are predicated of God, according to Boethius. (Boethius, On the Trinity 4–6 (PL 64:1252–56).) Therefore, God is composite.

Obj. 7: In everything there is substance, power, and activity, according to Dionysius; (Pseudo-Dionysius, The Celestial Hierarchy 11.2 (PG 3:283–86).) therefore, it seems that the activity follows the power and the substance. Now, there are several divine activities. Therefore, there is a plurality and composition in the divine substance.

Obj. 8: Wherever there is a plurality of forms, there must be composition. Now, in God there is a plurality of forms, for as the Commentator says, all forms exist actually in the first mover, just as they are potentially in prime matter. (Averroes, Commentary on the Metaphysics 11, comm. 18.) Therefore, composition is in God.

Obj. 9: Whatsoever is added to a thing that has complete being is accidental to it. Now, certain things are said of God based on time, such as that he is the Creator and the Lord. Therefore, these things are in him accidentally. But an accident with its subject forms a certain composition. Therefore, composition is in God.

Obj. 10: Where there are several real things, there is composition. Now, in God there are three persons, which are three realities, according to Augustine. (Augustine, On Christian Doctrine 1.5 (PL 34:21).) Therefore, composition is in God.

On the contrary (1), Hilary says: God is not composed of several things as man is, as though what he has were distinct from him who has it. (Hilary of Poitiers, On the Trinity 8.43 (PL 10:269).)

Furthermore (2), Boethius says: he is truly one since there is no number in him. (Boethius, On the Trinity 2 (PL 64:1250).) Now, where there is composition, there is some number. Therefore, God is without composition and utterly simple.

I answer that we must hold that God is simple in all ways, and for the present this may be proved by three arguments.

The first is as follows. We have proved in a former discussion that all beings proceed from a first existing being, which first being we call God. (Q. 3, a. 5.) Now, although in one and the same thing that is at one time in act, at another time in potency, potency precedes act in time but follows it in nature, yet simply speaking act precedes potency not only in nature, but also in time; for every being that is in potency is made actual by some actual being. Accordingly, the being that made all beings actual and itself proceeds from no other being must be the first thing in act, without any admixture of potency. For were it in any way in potency, there would be need of another previous being to make it actual. Now, in every composite of whatsoever kind of composition, there must be a mixture of act and potency. For in composites either one of the things from which it is composed is in potency to the other, as matter to form, subject to accident, genus to difference, or at least all the parts are in potency to the whole; for parts are reducible to matter, and the whole is reducible to form, as is clear in Physics 2, such that no composite can be the first act. (Aristotle, Physics 2.3, 195b12–20.) But the first being, which is God, must be pure act, as we have proved. (Q. 1, a. 1.) Therefore, it is impossible that God be composite; and thus, it follows that he is utterly simple.

The second reason is because, seeing that composition is only of diverse things, these different parts themselves require some agent to unite them together. For different things, as such, are not united. Now, every composite has being through the union of its component parts. Therefore, every composite depends on a preexisting agent. And consequently, the first being, which is God, from whom all things proceed, cannot be composite.

The third reason is because the first being, which is God, must be most perfect and consequently supremely good, since the principles of things are not imperfect, as Pythagoras and Leucippus contended. Now, the supremely good is that in which there is nothing lacking in goodness, just as the supremely white is that in which there is no admixture of blackness. But this is impossible in any composite thing. For a good that results from a composition of parts, and by which composition the whole is good, is not in any single part. Therefore, the parts are not good with the goodness proper to the whole. Consequently, that which is supremely good must be supremely simple and lacking in every composition. This argument is given by the Philosopher and by Hilary, where he says that God who is light is not composed of things that are dim, nor is he who is strength composed of things that are weak. (Aristotle, Metaphysics 11.1, 1059a34–37; 11.11, 1067b25–1072a23; 11.10, 1066b1–1067a37; Hilary of Poitiers, On the Trinity 7.27 (PL 10:223); cf. Metaphysics 12.7, 1072a23–b3.)

Reply Obj. 1: Aristotle does not mean that a multitude cannot proceed from one thing. For, since an agent produces its like, and since an effect falls short of reproducing its cause, it follows that where we find unity in the cause we shall find multiplicity in the effects; thus, in the sun’s power all the forms of generable bodies are, as it were, one, and yet they are distinct in the effects. So it is that by its one power a thing is able to produce various effects, just as fire by its heat liquefies and solidifies, softens and hardens, enflames and blackens. And man too by the power of his reason acquires various sciences and produces the various works of the arts. Therefore, much more so is God by his one simple power able to create many things. The Philosopher means, then, that a thing, so long as it remains the same, does not produce different effects at different times, if it acts by natural necessity, except perhaps accidentally through a diversity of the matter, or of some other accidental thing. But this is not to the point.

Reply Obj. 2: God is attained by the mind of the blessed, whole yet not wholly, because the mode of God’s knowableness infinitely surpasses the mode of a created intellect; and thus, a created intellect cannot understand God as perfectly as he can be understood, and consequently it cannot comprehend him.

Reply Obj. 3: By reason of one and the same thing, God is considered by us as having different kinds of causality; for because he is the first act, he is an agent, he is the exemplar of all forms, he is pure goodness, and consequently, the final cause of all things.

Reply Obj. 4: Property and essence in God do not differ in reality, but only in account, for the paternity itself is the divine essence, as we shall show further on. (Q. 8, a. 1.)

Reply Obj. 5: As the Philosopher says, nothing prevents contradictory statements from being verified about the same reality differing in account; thus, the same point in reality is both a beginning and an end by a difference of account; and considered as a beginning, it is not an end, and vice versa. (Aristotle, Physics 3.3, 202b8–29.) Therefore, since essence and property are the same in reality but differ in account, nothing prevents the one being common and the other incommunicable.

Reply Obj. 6: In God, the absolute and the relative do not differ in reality, but only in account, as stated above; therefore, we cannot infer that there is composition in him.

Reply Obj. 7: God’s activity may be considered from the point of view either of the one acting or of the thing done. If we consider it on the part of the one acting, then in God there is but one activity, and this is his own essence; for he produces things not by an action that is between God and the thing done but through his understanding and his will, which are his very being. If, however, we consider God’s activity on the part of the thing done, then there are various activities, the various effects of the divine operation. But this does not imply a composition in him.

Reply Obj. 8: The form of the effect is found in one way in a natural agent and in another in the agent acting by art. For the form of the effect is in the natural agent inasmuch as the agent produces an effect of like nature, since every agent produces its like. Now, this happens in two ways. When the effect becomes perfectly like the agent, insofar as it is proportionate to the agent’s power, then the form of the effect is in the agent according to the same account; this is clear in univocal agents, for instance, when a fire generates a fire. When, however, the effect does not become perfectly like the agent, insofar as it is not proportionate to the agent’s power, then the form of the effect is not in the agent according to the same account but in a more sublime manner; this is clear in equivocal agents, for instance, when the sun generates a fire.

On the other hand, in agents acting by art, the form of the effect pre-exists according to the same account but not by the same mode of being; for in the effect the form has a material being, while in the mind of the artisan it has intelligible being. Now, because something is said to be in the intellect as the thing that is understood and as the species by which it is understood, artificial forms are in the mind of the artisan as that by which the artwork is understood. For it is through conceiving the form of his artwork that the artisan produces it in the matter.

Accordingly, the forms of things are in God in both ways. For although he himself brings things about through his intellect, this is not without the action of nature. But in lower artisans, the art acts by the power of an extraneous nature that it employs as an instrument; for example, a brick maker uses fire to bake his bricks. On the other hand, God’s art employs no extraneous nature in its action; rather, it produces its effect by the power of his own nature. Hence, the forms of things are in the divine nature as in the power that produces them but not according to the same account, since no effect is equal to that power. Consequently, all forms that are manifold in his effects are in his power as one thing, such that their multiplicity argues no composition in him. Likewise, in his intellect there are many things understood through one thing, which is his essence. Now, it is no proof of composition in one who understands that he understands many things through one; therefore, neither from this point of view does it follow that there is composition in God.

Reply Obj. 9: Relations that are ascribed to God based on time are in him not really but only according to account. For a real relation is where something really depends on another, either simply speaking or in a certain respect. Hence, the relation of knowledge to what is knowable is real, while the relation of the knowable to the knowledge is only according to account, according to the Philosopher. (Aristotle, Metaphysics 5.15, 1020b26–1021b11.) Since, then, God depends on no other being, but on the contrary all things depend on him, other things bear a real relation to God, while his relation to them is only a relation according to reason, inasmuch as that the intellect is unable to understand that A is related to B without conceiving a corresponding relation of B to A.

Reply Obj. 10: The plurality of the persons does not imply a composition in God. For the persons may be considered in two ways.

First, in reference to the essence, with which they are really identical; and thus, it is clear that there is no composition here.

Second, in reference to one another; and thus, they are regarded as mutually distinct, not as united together. Therefore, from this point of view again there is no composition, since every composition implies union.