SECOND ARTICLE [I, Q. 10, Art. 2]

Whether God is Eternal?

Objection 1: It seems that God is not eternal. For nothing made can be

predicated of God; for Boethius says (De Trin. iv) that, "The now that

flows away makes time, the now that stands still makes eternity;" and

Augustine says (Octog. Tri. Quaest. qu. 28) "that God is the author of

eternity." Therefore God is not eternal.

Obj. 2: Further, what is before eternity, and after eternity, is

not measured by eternity. But, as Aristotle says (De Causis), "God is

before eternity and He is after eternity": for it is written that "the

Lord shall reign for eternity, and beyond [*Douay: 'for ever and

ever']" (Ex. 15:18). Therefore to be eternal does not belong to God.

Obj. 3: Further, eternity is a kind of measure. But to be measured

belongs not to God. Therefore it does not belong to Him to be eternal.

Obj. 4: Further, in eternity, there is no present, past or future,

since it is simultaneously whole; as was said in the preceding

article. But words denoting present, past and future time are applied

to God in Scripture. Therefore God is not eternal.

_On the contrary,_ Athanasius says in his Creed: "The Father is eternal,

the Son is eternal, the Holy Ghost is eternal."

_I answer that,_ The idea of eternity follows immutability, as the idea

of time follows movement, as appears from the preceding article.

Hence, as God is supremely immutable, it supremely belongs to Him to

be eternal. Nor is He eternal only; but He is His own eternity;

whereas, no other being is its own duration, as no other is its own

being. Now God is His own uniform being; and hence as He is His own

essence, so He is His own eternity.

Reply Obj. 1: The "now" that stands still, is said to make eternity

according to our apprehension. As the apprehension of time is caused

in us by the fact that we apprehend the flow of the "now," so the

apprehension of eternity is caused in us by our apprehending the

"now" standing still. When Augustine says that "God is the author of

eternity," this is to be understood of participated eternity. For God

communicates His eternity to some in the same way as He communicates

His immutability.

Reply Obj. 2: From this appears the answer to the Second Objection.

For God is said to be before eternity, according as it is shared by

immaterial substances. Hence, also, in the same book, it is said that

"intelligence is equal to eternity." In the words of Exodus, "The

Lord shall reign for eternity, and beyond," eternity stands for age,

as another rendering has it. Thus it is said that the Lord will reign

beyond eternity, inasmuch as He endures beyond every age, i.e. beyond

every kind of duration. For age is nothing more than the period of

each thing, as is said in the book _De Coelo_ i. Or to reign beyond

eternity can be taken to mean that if any other thing were conceived

to exist for ever, as the movement of the heavens according to some

philosophers, then God would still reign beyond, inasmuch as His

reign is simultaneously whole.

Reply Obj. 3: Eternity is nothing else but God Himself. Hence God is

not called eternal, as if He were in any way measured; but the idea

of measurement is there taken according to the apprehension of our

mind alone.

Reply Obj. 4: Words denoting different times are applied to God,

because His eternity includes all times; not as if He Himself were

altered through present, past and future.

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Summa Theologica, Part I (Prima Pars) From the Complete American Edition · 第 73 / 722 题