Back to meat and potatoes this week, which has the slug: There can be only One.
1 Now although intellectual substances are not corporeal, nor composed of matter and form, nor existing in matter as material forms, we must not think that they equal the divine simplicity. For a certain composition is to be found in them, forasmuch as in them being is not the same as what is.
2 For if being is subsistent, nothing besides being is added thereto. Because even in those things whose being is not subsistent, that which is in an existing thing beside its being, is indeed united to the existing thing, but it is not one with its being, except accidentally, in so far as there is one subject having being and that which is beside being: thus it is clear that in Socrates, beside his substantial being, there is white, which is distinct from his substantial being, since to be Socrates and to be white are not the same save accidentally. Consequently if being is not in a subject, there will remain no way in which that which is beside being can be united to it. Now being, as being, cannot be diverse, but it can be differentiated by something beside being: thus the being of a stone is other than the being of a man. Hence that which is subsistent being can be one only. Now it was shown above that God is His own subsistent being: wherefore nothing beside Him can be its own being. Therefore in every substance beside Him, the substance itself must needs be distinct from its being.
Notes The point of this is that even though our intellects are not made of bodies, are not corporeal, they are still different from being itself. Weak analogy: Numbers are not corporeal, but there is a difference between 2 and 3, which means that difference has to manifest itself in some way.
3 Moreover. A common nature, if considered in the abstract, can only be one: although those that have that nature may be found to be many. For if the nature of animal subsisted as separate by itself, it would not have the things belonging to a man or to an ox. Now if we remove the differences which constitute a species, there remains the nature of the genus without division, since the same differences constitute the species, which divide the genus. Accordingly, if being itself is common like a genus, a separate self-subsistent being can only be one. If, however, it be not divided by differences, as a genus is, but, as it is in truth, by the fact that it is the being of this or that, it is yet more evident that what exists of itself can only be one. It follows, therefore, since God is subsistent being, that nothing beside Him is its own being.
Notes Read this one through once or twice and you’ll get it. There are two or more species under one genus, and there are differences between genuses and that these differences have to flow from something, and the direction is toward being itself, which is God.
4 Again. There cannot possibly be a twofold being absolutely infinite, for being that is absolutely infinite contains every perfection of being, so that if two things had such an infinity, there would be nothing in which they differed. Now subsistent being must needs be infinite, because it is not limited by any recipient. Therefore there cannot be any subsistent being outside the first.
Notes Remember: we’re way beyond mere counting infinity here. We talking the infinity of infinities. And as the man said, There Can Be Only One.
5 Again. If there is a self-subsistent being, nothing is applicable to it except that which belongs to a being as being: since what is said of a thing, not as such, is not applicable thereto except accidentally, by reason of the subject: so that if we suppose it to be separated from its subject, it is nowise applicable to it. Now to be caused by another is not applicable to a being, as being, otherwise every being would be caused by another, and consequently we should have to proceed to infinity in causes, which is impossible, as shown above. Therefore that being which is subsistent, must needs not be caused. Therefore no caused being is its own being.
Notes ¡Hola! There it is. No caused being is its own being. God is not, was not, caused. God is: “I Am that I Am.” See paragraph 9 below. It really is impossible for us to think outside of time, and the failure to appreciate this accounts for the perpetual oh-yeah arguments of atheism. “Oh yeah? Then who created God, smart guy?”
6 Moreover. The substance of a thing appertains to it of itself and not by another: wherefore to be actually lightsome is not of the air’s substance, since it comes to it from something else. Now every created thing has being from another, else it would not be caused. Therefore in no created being is its being the same as its substance.
7 Again. Since every agent acts in so far as it is actual, it belongs to the first agent which is most perfect to be actual in the most perfect way. Now a thing is the more perfectly actual, the more its actuality is posterior in the order of generation, for actuality is posterior in time to the potentiality in the one and same subject which passes from potentiality to actuality. Also act itself is more perfectly actual than that which has act, for the latter is actual on account of the former. Accordingly, these premisses being supposed, it is clear from what has been already proved that God alone is the first agent. Therefore it belongs to Him alone to be actual in the most perfect way, to be, that is, the most perfect act. Now this is being, in which generation and all movement terminates: since every form and act is in potentiality before it acquires being. Therefore it belongs to God alone to be His own being, just as it belongs to Him alone to be the first agent.
Notes Put it this way: you have to start somewhere in creation. And that must be God.
8 Moreover. Being itself belongs to the first agent in respect of His proper nature: for God’s being is His substance, as we have proved above. Now that which belongs to a thing in respect of its proper nature, does not belong to others except by way of participation; as heat to other bodies than fire. Wherefore being itself belongs to all others except the first agent by a kind of participation. But that which belongs to a thing by participation is not its substance. Therefore it is impossible that the substance of a thing other than the first agent, should be being itself.
9 Hence (Exod. iii. 14) the name proper to God is stated to be WHO IS, because it is proper to Him alone that His substance is not distinct from His being.