See the Introduction here.
The argument begins simply: “From God I proceeded.” (John 8:24) Question 27 is the foundation for the Treatise on the Trinity, and this appeal to authority – in this case, Divine Authority – is the point of departure. God has said it, therefore we believe it, as God does not lie and is never confused or ignorant.
It must begin this way, as we will see later in detail; for now it suffices to say that what can be known about God by reason alone does not include real processions of the sort which we are about to discuss. God must in fact tell us there are processions in Himself. With that, let us begin.
Article 1 establishes the presence of procession in God. Article 2 demonstrates that one procession is rightly called “generation” (of the Word, or the Son). Article 3 shows that there is another procession in God, that of the Holy Spirit. Article 4 determines that the procession of the Holy Spirit is not “generation” but “spiration.” Article 5 proves there cannot be more than two processions in God (and thus not more than three Persons).
The “sed contra” of Article 1 has already been laid out – John 8:24 tells us that procession exists in God. We move now to the body of Article 1 (the “respondeo” or “answer”) before looking at the objections (which is the proper way to read the Summa, by the way) and the other Articles.
Thomas again begins with Scripture. The Bible uses Names for God which imply procession (like “Son”) but it is not immediately clear what kind of procession this is. A procession, in general, is a kind of “issuing forth” of one thing from another – the way a son proceeds from a father… But now we see the two great errors which are possible: Arianism and Sabellianism.
Arianism sees the Son as a creature of the Father, and the Holy Spirit as a creature of both – this would be procession indeed, but this position empties the Son and the Holy Spirit of Divinity. (Thomas again appeals to Scripture to explain why Arius was wrong, specifically 1 John 5:20 for the Son, and 1 Corinthians 6:19 for the Holy Spirit… I hope it is sufficiently clear by now that Thomas’s theology is deeply Biblical; we are not even half-way through Article 1.)
Sabellianism (also Modalism) sees the Son and the Holy Spirit not as creatures but simply Names predicated of God the Father acting in certain ways. When the Father is Incarnate, He is called “Son.” When He sanctified human souls, He is called “Holy Spirit.” In other words, the Son and the Holy Spirit are only logical distinctions – they are not really distinct from the Father. Thomas appeals to John 5:19 and “many other passages” to rebut this… This simply is not what we get from Christ’s teaching in Scripture.
The common error is to see procession as “outward” – something existing in creation. With Arius, it is the beings themselves which are processed outwardly, while with Sabellius the outward effect which proceeds from Divine operation in creation indicates the Name to use.
This is not the kind of procession which allows for the Trinity of Catholic Faith. The processions of the Trinity are interior processions.
The most evident analogy is with our own mind (an analogy developed at length by St. Augustine in his book on the Trinity frequently called the “psychological analogy”). We think of a thing by conjuring an idea – but the idea remains within our mind until we speak it by the word, the concept, by which we are understanding it. In God, procession is like this – it is not procession as according to bodies, such as a son proceeding from a father, or heat proceeding from fire.
You can look at Objections 1 and 3 on your own. Objection 2 is worth a look here, as it really touches the heart of the major obstacle to making sense of the Trinity, namely, Divine Simplicity. After all, what proceeds from a thing is distinct from that whence it proceeds – but God is perfectly simple. How? Well, in an intellectual procession, the more perfect the procession is the more closely united is the concept with the mind. In other words, the better a thing is known, the more it is one with the intellect. God knows perfectly – so what He conceives of must be perfectly united with Him by Essence. (We will see a similar argument about power later – the more power a cause has, the more the cause will be replicated in the effect… the better the teacher, the more able the students will be to teach what they are learning. Coincidentally, this is part of why Jesus did not write a book. But we are getting sidetracked…) The point is that the Word is perfectly understood by the Father and is therefore perfectly One with Him.
So much for Article 1. There are processions in God which remain within God, the most easily grasped being the intellectual procession of the Word, Who is perfectly united with the Father because the Father perfectly understands the Word. On to Article 2: is any procession in God called “generation”?
The “sed contra” is Psalm 2:7 – “This day I have begotten Thee.” (To “beget” and to “generate” are the same.) So, at least one procession in God is called “generation.” But why?
There are two kinds of generation – the kind which makes something new (fire making more fire) which brings something into existence out of non-existence, and a kind which is proper to living things which generate other living things which have the same specific nature (unlike a man producing a hair on his head – but like a man producing a man). The latter normally includes the “making” of the first kind of generation; a horse generates a horse, a man generates a man, and so on. But maybe there could be something which lacks the aspect of “making” and has only this latter kind of generation… This is the Father-Son relationship. This generation is from a living principle (the Father, Whose operation of understanding is the “force” of this generation), it is a generation of similitude (due to how understanding works, as explained above), and that which is being understood is God Himself, the Divine Essence (the same nature as the Generator). So this is living generation but without creation. (Nerds may look at Question 14 for more details.)
Objections 2 and 3 are very important and very helpful.
Objection 2 notes that our own thoughts are not called “generation.” So, why should God’s thought in this case be called “generation”? Well, our act of understanding is not the same as our own substance – this is not the case with God. We produce thoughts that are not ourselves; but for God, anything in Him is Him.
Objection 3 argues that what derives its existence from another will exist in a subject, meaning, it is not self-subsistent – for example, a horse generated from a horse will exist in the physical universe, as part of that universe. So, since God is self-subsistent, there can be no generation in Him. Well, the created universe is Thomas’ counter-example: it does not exist in a subject. Creation exists in itself, due to the power of God. So, the Word, Who derives or receives His existence from another (the Father) by interior procession, does not need to subsist in another, just like creation does not need to.
Article 3 is relatively simple. The “sed contra” points to Scripture for the grounds for arguing that the Holy Spirit proceeds from God but is not the Word (John 15:26 and John 14:16 respectively).
The intellect has an interior procession, and so does the will. In the will, the object of desire moves us towards that object by a kind of impulsion. In God, the intellectual procession generates the Word; the procession of the Will of God gives us the Holy Spirit. This is the procession of love.
Objections 1 and 3 are good to look at.
Objection 1 states that, if we admit of more than one procession in God, we could be setting ourselves up to say that there are infinite processions in God, which is unreasonable. Thomas’ response is very important (and essentially constitutes the argument of Article 5)… Only the intellect and the will can have interior processions, so there cannot be more than two.
Objection 3 is possibly the strongest counter-argument yet. The claim is that intellect and will are the same in God, due to Divine Simplicity. Therefore, there cannot be a difference in the procession from the Divine Intellect and Will… So, there can be only one procession. Thomas admits that the Will and Intellect of God are the same, but Thomas says that there is a priority between intellect and will, with intellection preceding willing, logically even if not really; in God, this priority can only be logical – one must know what one loves, but since God is not doing this “step by step” it is in a single moment… and yet, there really is this logical priority, so there can be distinct processions. (Nerds might like to recall the insistence of Thomas on the priority of the intellect in human acts, over and against Bonaventure and later Scotus, Ockham, and then the long line of nominalists and voluntarists… Interesting how this connects, no?)
Article 4 gives us the first appeal to something other than Scripture – rather, it is an appeal to St. Athanasius, who says that the Holy Spirit is not begotten (or generated).
The intellect has an interior procession because some similitude exists in the intellect (I think of the apple, and something like an apple is in my mind – I think of myself, and something like myself is in my mind – and the better the conception in my mind is, the more like the thing itself that it is a conception of will be… in God, as we saw, this conception is perfect, and therefore is God Himself, God the Word). Well, with the will it is a bit different. Instead of similitude, we speak of inclination, or a kind of wanting (or loving). When we have an object in our will, we are inclined towards it – we want it, we desire it, we love it. God, by loving Himself, has an interior procession in His Will. What thus proceeds is the Holy Spirit, so called because “spirit” implies a kind of living impulse. The procession is therefore called “spiration” rather than generation (see Objection 3).
We’ll leave the Objections alone.
Article 5 is within our grasp, as we’ve already indicated the argument. The “sed contra” is particularly blunt at this point – Thomas simply says there are only two Persons Who proceed, and thus there are only two processions.
As we have said, the intellect and the will are the only faculties which can have interior processions. Other faculties or operations will have exterior processions or no processions at all – sensation, for instance, requires activity outside the intellectual nature. Thus, there can only be three Persons in God, in accord with the Intellect and Will and unproceeded Principle, the Father.
The Objections concern the following claims: 1, that power has procession; 2, that goodness involves procession; and 3, that fecundity of operations would multiply the processions of Word and Love.
As for 1, power is exercised on another, so it is an external operation. As for 2, the goodness of God belongs to His Essence and is not an operation like understanding or willing, and so the Goodness of God is simply involved in the processions of the Word and Love. As for 3, God understands all and loves all by one simple act – therefore, there is no possibility of multiplying the processions of Word and Love.
We made it! Question 27, done! Believe it or not, we have already pretty much laid out the entirety of Trinitarian theology in seed form. The rest is largely just unpacking what we have just done.
Next up, Question 28: relations of origin…