1. Having examined various possible modes of composition in God, St. Thomas summarizes what precedes by asking whether God is altogether simple (omnino simplex). Against the simplicity of God he proposes two objections.
2. The first objection follows from the principle that every agent imparts its likeness upon the things it affects (omne agens agit sibi simile). Since God’s likeness is present in creatures, if God were utterly simple, one would expect at least some creatures to have this characteristic as well. But since no creature has it, it seems that God must not have it either.
3. The second objection is from an observation about perfections among creatures: that what is better is usually more complex. Thus blocks of steel and plastic are less perfect than trains and cars. Bacteria are less perfect than elephants, etc. But since God is the most excellent, he cannot be altogether simple.
4. For the Sed Contra he cites Augustine.
5. In the corpus, he gives five arguments for God’s total simplicity. First, he summarizes the preceding articles of this question: since God is not composed in any of the individual ways that a thing can be composed (of quantitative parts, of matter and form, of nature and supposit, of essence and existence, of genus and difference, of subject and accident), it seems that he cannot be composite.
6. Second, he observes that every composite is posterior to and dependent upon its components. (Since without its component parts a composite ceases to be.) Since God is the first being, he cannot be dependent in this way, and thus cannot be composed.
7. Third, he observes that composites are always caused, since in a composite diverse things come together as one, and the union of diverse things does not come about except through some external cause.
8. Fourth, that in composites there is always potency to change, because the components are in potency to decomposition, just as they were in potency to composition prior to their union in the composite.
9. Fifth, he says that in a composite there is always some form of the whole which cannot be predicated of any of its parts. In homogeneous substances this is the quantity of matter, which differs between the whole and the parts, though its specific form may be the same throughout. In complex substances, these are the organs or diverse parts which differ not only in material quantity but also in their act from the whole to which they contribute. Thus if God were composite, there would be in God some part which was not God. But while this sort of thing is appropriate for individual things which participate in forms, in God form and supposit are identical, which means that whatever God is, is purely and utterly exhausted by his own existence. God is the pure form of Divinity, and not an instantiation of it. Therefore there cannot be anything distinct from Divinity in God, or any parts.
10. To the first objection he replies that while everything that God makes imitates him, it imitates him in the fashion of a creature, to which it belongs to be composed of essence and existence, as discussed later on (Q.4 A.3).
11. To the second objection he replies that among creatures composites are better than simple things because no simple creature, on account of its finitude, can embody all of the perfections of the Godhead.
OUTLINE OF ARTICLE
– Creatures resemble their creator, but no creature is simple, so God must not be simple.
– Among creatures the more complex are better, so it would be unreasonable to suppose that God, the greatest being, is utterly simple.
– God is not composed in any of the particular ways a thing can be composed.
– Composites are posterior and dependent.
– Composites are caused.
– Composites are in potency.
– In a composite the form of the part always differs from the form of the whole, but God, being pure form, cannot be in any way other than what he is, so he must be utterly simple.
– Creatures are like God to a certain extent, but only God is perfectly simple.
– Complex creatures are superior inasmuch as they incorporate different aspects of the divine perfection, which no creature can represent fully in its simplicity.