QUESTION V.
Whether the trinity of persons is compatible with supreme eternity.
Next it is asked whether the trinity of persons is compatible with supreme eternity. And concerning this, two things are asked.
The first is whether the divine being is eternal. The second is whether trinity and eternity are compatible.
ARTICLE I.
Whether the divine being is eternal.
Concerning the first, we proceed as follows. And that the divine being is eternal:
1. The authority of Scripture demonstrates this, Exodus 15: The Lord shall reign forever and ever; and Romans 1: His eternal power also and divinity.
2. The truth of the faith also demonstrates this: " Eternal the Father," it says in the Athanasian Creed, "eternal the Son, eternal the Holy Spirit."
3. Likewise, the necessity of reason concludes this same thing. For Richard argues thus: Everything that is from itself is eternal; but the divine being, since it is first, is from itself: therefore, etc. The major is manifest; because if it were not eternal, at some point it would not have existed, and then it would never have given being either to itself or to others, and consequently it would never exist. The minor is evident through itself.
4. Likewise, everything that is its own being is eternal; for being cannot not be, therefore it can neither begin nor cease, and thus it lacks a beginning and an end: if therefore God, since he is most simple, is his own being, indeed is simply being itself; therefore he is altogether eternal.
5. Likewise, everything that is truth itself is eternal; but the divine being is truth itself: therefore, etc. The minor is evident: Augustine proves the major in the Soliloquies: For truth can neither be thought nor declared not to be: indeed it follows that if there is no truth, some truth exists, because if there is no truth, it is true that there is no truth, or that it does not exist: therefore being cannot in any way be removed from truth: therefore it always was, is, and will be.
6. Likewise, everything in which there is supreme infinity is eternal; for if it had begun, it would be of finite duration; but the divine being is infinite: therefore it is necessary that it be eternal; otherwise, if it lacks eternity, it also lacks immensity.
7. Likewise, everything in which there is supreme immortality is eternal; "for what begins from change tends toward change"; but in the divine being there is supreme immortality, since it is life itself through essence, or living itself: therefore it is necessary that the divine being possess eternity.
8. Again, everything in which there is supreme happiness, is eternal; but the divine being is of this kind, since it is most perfect: therefore etc. The major is proved, because that happiness which lacks beginning and end is greater than that which took its origin from elsewhere: if therefore the divine being is most happy, it follows necessarily that it is eternal. And again, all happiness implies the absence of an end : therefore the most perfect happiness implies the lack of every beginning.
9. Again, everything in which there is supreme simplicity, is eternal; the divine being is of this kind: therefore etc. The minor is manifest: the major is proved: because in whatever there is supreme simplicity, first, middle, and last do not differ, and nothing of this kind has past and future, but only an abiding present: but everything of this kind is eternal: therefore etc.
10. Again, since being is divided into the eternal and the aeviternal and the temporal, the aeviternal is nobler than the temporal, and the eternal is nobler than both; but what is nobler must always be attributed to the noblest being: therefore supreme eternity must be attributed to God.
11. Again, everything flowing is reduced to something permanent: therefore a flowing duration is reduced to a permanent duration, and therefore a present passing into the past is reduced to an ever-abiding present: but such a present does not exist in a defective thing: therefore it is necessary that it exist in the creative essence: therefore it is necessary that the divine being be eternal.
12. Again, the true concerning the future was true without a beginning, and the true concerning the past is true without an end: but the future and the past are necessarily reduced to the present: therefore it is necessary to posit a true that is always present without end and without beginning. But this is eternal, nor can it be posited in anything other than in relation to the first principle: therefore necessarily the divine being is eternal.
To the contrary: 1. Eternity is a measure; but nothing immeasurable has a measure, for if it has a measure, it is not immeasurable: therefore etc.
2. Again, a measure is equal to the measured; but nothing can be equal to the divine being: therefore there is no duration of eternity in God.
3. Again, eternity is the lack of end and beginning; but nothing lacks that which it is: if therefore God is the beginning and end of all things, then the divine being does not have a lack of these: therefore it cannot be eternal.
4. Again, the lack of completion implies a defect: beginning and end express completion: therefore in God there is no positing a privation of these: but eternity expresses a privation of these: therefore it ought not to be posited concerning the divine being.
5. Again, eternity is the lack of past and future; but God truly was and is and will be: therefore the divine being does not have the character of the eternal.
6. Again, let A be past time, B future; it is true to say that God was in A and will be in B, and false conversely: therefore A has truly passed away in relation to God, and B is truly future: therefore the divine being has a past and a future: therefore it is not eternal.