It’s going to get rough the next couple of weeks, since the subject is the Trinity and the filioque, which you will recall caused something of a ruckus. As important as this subject is, it is the very last (truly) thing that should divide us today.
1 When all things are carefully considered, it is clear and manifest that sacred Scripture proposes this for belief about the divine generation: that the Father and Son, although distinguished as persons, are nevertheless one God and have one essence or nature. But one finds this far removed from the nature of creatures: that any two be distinguished in supposit, yet one in their essence; so, human reason, proceeding from the properties of things, experiences difficulties in a great variety of ways in this secret of divine generation.
Notes Reminder that his week are the contra arguments. These are refuted in the weeks to come.
2 Since the generation known to us is a certain mutation to which corruption is opposed, it seems hard to put generation in God, who is immutable, incorruptible, and eternal, as is clear from the foregoing.
3 If generation, moreover, is a change, whatever is generated must be changeable. But what is changed goes from potency to act, for “change is the act of the potential as such.” If, therefore, the Son of God is begotten, He is not eternal, it seems, as one going from potency to act; nor is He true God, since He is not pure act, but something which has potentiality.
4 The begotten, furthermore, receives its nature from the generator. If, then, the Son is begotten by the Father, it follows that He has received the nature which He has from the Father. But it is not possible that He has received from the Father a nature numerically other than the Father has, but the same in species, as happens in univocal generations, when man generates man, or fire, fire. For we showed above the impossibility of a numerical plurality of deities.
It seems equally impossible that He has received nature numerically the same as the Father has. For, if He receives a part of it, it follows that the divine nature is divisible; but, if the whole is transfused into the Son, it ceases to be in the Father; and so, in generation, the Father is corrupted.
Nor, again, can it be said that by a kind of exuberance the divine nature flows from the Father to the Son, as the water of a spring flows into a stream and the spring is not emptied, for the divine nature cannot be divided, just as it cannot be increased. It seems, therefore, to remain that the Son has received from the Father a nature which is neither in number nor in species the same as the Father’s, but of another genus altogether. This is what happens in equivocal generation when animals born of putrefaction are generated by the power of the sun, but do not belong to its species. It follows, then, that the Son of God is neither a true Son, since the Father’s species is not His; nor true God, since He does not receive the divine nature.
5 If the Son, again, receives a nature from God the Father, the recipient in Him must be other than the nature received, for nothing receives itself. The Son, then, is not His own essence or nature. Therefore, He is not true God.
6 Moreover, let the Son be not other than the divine essence; let the divine essence be something subsistent, as was proved in Book I; clearly, the Father, also, is the divine essence. The conclusion appears to be that the Father and Son coincide in the very same subsisting thing. Now, “the subsistent thing in intellectual natures is called a person.” It follows, then, that if the Son is Himself the divine essence the Father and the Son coincide in person. But if the Son is not the very divine essence He is not true God. For we proved this about God in Book I. It seems, therefore, either that the Son was not true God, as Arius used to say, or that personally He is not other than the Father, as Sabellius asserted.
7 Furthermore, that in a thing which is the principle of its individuation cannot possibly be in a second thing distinguished as a supposit from the first. For what is in many is not a principle of individuation. But the essence of God is that by which God is individuated, for the essence of God is not a form in matter so that God could be individuated by matter. There is, therefore, nothing in God the Father by which He might be individuated except His essence. Therefore, His essence cannot be in any other supposit. His essence, therefore, is not in the Son, and so the Son is not true God, following Arius; or the Son is not other in supposit than the Father, and so the Person of each is the same, following Sabellius.
8 Again, if the Father and Son are two supposits or two Persons, yet are one in essence, there must be in them something other than the essence by which they are distinguished, for a common essence is ascribed to each and what is common cannot be a distinguishing principle. Therefore, that which distinguishes the Father from the Son must be other than the divine essence. The Person of the Son, then, is a composite of two, and so is the Person of the Father a composite of two: the common essence and the distinguishing principle. Therefore, each of the two is a composite and neither of the two is true God.
9 But one may say that they are distinguished by a relation only, inasmuch as one is the Father, the other the Son. What is predicated relatively, however, seems not to predicate a something in that of which it is said, but rather a to something. Thus, by such predication no composition is brought in. But this answer appears not adequate for avoiding the awkward results just mentioned.
10 [For there can be no relation without something absolute. In whatever is relative there must be understood that which is said of itself (ad se) and, additionally, that which is said referring to another (ad aliud). Thus is something said absolutely of “servant” and, additionally, something is said referring “to the master.” Therefore, that relation by which the Father and the Son are distinguished must have something absolute on which it is founded.
Now, then, either that absolute is one only, or there are two absolutes. If it is one only, a twofold relation cannot be founded upon it, unless, of course, it be a relation of identity which can produce no distinction—as when one says that the same is the same as the same. Therefore, if the relation be such that it calls for a distinction, there must be a prior understanding of a distinction of absolutes. Accordingly, it does not seem possible that the Persons of the Father and the Son are distinguished by relations only.
11 One ought, along the same line, to say that the relation which distinguishes the Son from the Father either is a thing or is in the intellect alone. Let it, then, be a thing, and it seems not to be that thing which is the divine essence, since the divine essence is common to the Father and the Son. Therefore, in the Son there will be something which is not His essence. Thus, He is not true God, for we showed in Book I that there is nothing in God which is not His essence. But let that relation be in the intellect only, and it cannot, then, distinguish the Son from the Father personally, for things which are personally distinguished must be really distinguished.
12 Again, every relative depends on its correlative. But what depends on another is not true God. If, then, the persons of the Father and the Son are distinguished by relations, neither of them is true God.
13 If the Father, moreover, is God and the Son is God, this name “God” ought to be predicated substantially of the Father and the Son, since divinity cannot be an accident.” But a substantial predicate is truly that of which it is predicated. For, when one says “Man is animal,” what is truly man is animal; in the same way, when one says “Socrates is man,” what is truly Socrates is man. And from this there seems to follow the impossibility of discovering a plurality on the part of the subjects when there is unity on the part of the substantial predicate: Socrates and Plato are not one man, although they are one in humanity. Nor are man and ass one animal, although they are one in animal. Therefore, if the Father and the Son are two Persons, it seems impossible that they are one God.
14 Opposed predicates, furthermore, show a plurality in that of which they are predicated. But opposites are predicated of God the Father and of God the Son. The Father is God unbegotten and generating, but the Son is God begotten. Therefore, it does not seem possible that the Father and Son are one God.
15 These, then, and others like these are the arguments by which some whose will it is to measure divine mysteries by their own reason strive to attack divine generation. But, because truth is strong in itself and is overcome by no attack, it must be our intention to show that the truth of faith cannot he overcome by reason.