In today’s Catechism sections, we continue reading about the attributes of God, including His eternity and His perfection of Truth. St. Thomas Aquinas provides the supplementary material from his Summa Theologica.

"A God merciful and gracious"

210 After Israel's sin, when the people had turned away from God to worship the golden calf, God hears Moses' prayer of intercession and agrees to walk in the midst of an unfaithful people, thus demonstrating his love.18 When Moses asks to see his glory, God responds "I will make all my goodness pass before you, and will proclaim before you my name "the LORD" [YHWH]."19 Then the LORD passes before Moses and proclaims, "YHWH, YHWH, a God merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness"; Moses then confesses that the LORD is a forgiving God.20

211 The divine name, "I Am" or "He Is", expresses God's faithfulness: despite the faithlessness of men's sin and the punishment it deserves, he keeps "steadfast love for thousands".21 By going so far as to give up his own Son for us, God reveals that he is "rich in mercy".22 By giving his life to free us from sin, Jesus reveals that he himself bears the divine name: "When you have lifted up the Son of man, then you will realize that "I AM"."23

God alone IS

212 Over the centuries, Israel's faith was able to manifest and deepen realization of the riches contained in the revelation of the divine name. God is unique; there are no other gods besides him.24

He transcends the world and history. He made heaven and earth: "They will perish, but you endure; they will all wear out like a garment....but you are the same, and your years have no end."25

In God "there is no variation or shadow due to change."26 God is "HE WHO IS", from everlasting to everlasting, and as such remains ever faithful to himself and to his promises.

213 The revelation of the ineffable name "I AM WHO AM" contains then the truth that God alone IS. The Greek Septuagint translation of the Hebrew Scriptures, and following it the Church's Tradition, understood the divine name in this sense: God is the fullness of Being and of every perfection, without origin and without end. All creatures receive all that they are and have from him; but he alone is his very being, and he is of himself everything that he is.


214 God, "HE WHO IS", revealed himself to Israel as the one "abounding in steadfast love and faithfulness".27 These two terms express summarily the riches of the divine name. In all his works God displays, not only his kindness, goodness, grace and steadfast love, but also his trustworthiness, constancy, faithfulness and truth. "I give thanks to your name for your steadfast love and your faithfulness."28 He is the Truth, for "God is light and in him there is no darkness"; "God is love", as the apostle John teaches.29

God is Truth

215 "The sum of your word is truth; and every one of your righteous ordinances endures forever."30 "and now, O LORD God, you are God, and your words are true";31 this is why God's promises always come true.32 God is Truth itself, whose words cannot deceive. This is why one can abandon oneself in full trust to the truth and faithfulness of his word in all things. The beginning of sin and of man's fall was due to a lie of the tempter who induced doubt of God's word, kindness and faithfulness.

216 God's truth is his wisdom, which commands the whole created order and governs the world.33 God, who alone made heaven and earth, can alone impart true knowledge of every created thing in relation to himself.34

217 God is also truthful when he reveals himself - the teaching that comes from God is "true instruction".35 When he sends his Son into the world it will be "to bear witness to the truth":36 "We know that the Son of God has come and has given us understanding, to know him who is true."37


228 "Hear, O Israel, the LORD our God is one LORD..." (⇒ Dt 6:4; ⇒ Mk 12:29). "The supreme being must be unique, without equal. . . If God is not one, he is not God" (Tertullian, Adv. Marc., 1, 3, 5: PL 2, 274).

229 Faith in God leads us to turn to him alone as our first origin and our ultimate goal, and neither to prefer anything to him nor to substitute anything for him.

230 Even when he reveals himself, God remains a mystery beyond words: "If you understood him, it would not be God" (St. Augustine, Sermo 52, 6, 16: PL 38, 360 and Sermo 117, 3, 5: PL 38, 663).

231 The God of our faith has revealed himself as HE WHO IS; and he has made himself known as "abounding in steadfast love and faithfulness" (⇒ Ex 34:6). God's very being is Truth and Love.

Aquinas discusses the eternal aspect of God in the Summa Theologica (1, 10).

Article 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.

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

Objection 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.

Objection 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 to Objection 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 to Objection 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 to Objection 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 to Objection 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.

Also in the Summa Theologica, St. Thomas Aquinas discusses God as Truth. (1, 16)

Article 5. Whether God is truth?

Objection 1. It seems that God is not truth. For truth consists in the intellect composing and dividing. But in God there is not composition and division. Therefore in Him there is not truth.

Objection 2. Further, truth, according to Augustine (De Vera Relig. xxxvi) is a "likeness to the principle." But in God there is no likeness to a principle. Therefore in God there is not truth.

Objection 3. Further, whatever is said of God, is said of Him as of the first cause of all things; thus the being of God is the cause of all being; and His goodness the cause of all good. If therefore there is truth in God, all truth will be from Him. But it is true that someone sins. Therefore this will be from God; which is evidently false.

On the contrary, Our Lord says, "I am the Way, the Truth, and the Life" (John 14:6).

I answer that, As said above (Article 1), truth is found in the intellect according as it apprehends a thing as it is; and in things according as they have being conformable to an intellect. This is to the greatest degree found in God. For His being is not only conformed to His intellect, but it is the very act of His intellect; and His act of understanding is the measure and cause of every other being and of every other intellect, and He Himself is His own existence and act of understanding. Whence it follows not only that truth is in Him, but that He is truth itself, and the sovereign and first truth.

Reply to Objection 1. Although in the divine intellect there is neither composition nor division, yet in His simple act of intelligence He judges of all things and knows all things complex; and thus there is truth in His intellect.

Reply to Objection 2. The truth of our intellect is according to its conformity with its principle, that is to say, to the things from which it receives knowledge. The truth also of things is according to their conformity with their principle, namely, the divine intellect. Now this cannot be said, properly speaking, of divine truth; unless perhaps in so far as truth is appropriated to the Son, Who has a principle. But if we speak of divine truth in its essence, we cannot understand this unless the affirmative must be resolved into the negative, as when one says: "the Father is of Himself, because He is not from another." Similarly, the divine truth can be called a "likeness to the principle," inasmuch as His existence is not dissimilar to His intellect.

Reply to Objection 3. Not-being and privation have no truth of themselves, but only in the apprehension of the intellect. Now all apprehension of the intellect is from God. Hence all the truth that exists in the statement--"that a person commits fornication is true"--is entirely from God. But to argue, "Therefore that this person fornicates is from God", is a fallacy of Accident.

Article 6. Whether there is only one truth, according to which all things are true?

Objection 1. It seems that there is only one truth, according to which all things are true. For according to Augustine (De Trin. xv, 1), "nothing is greater than the mind of man, except God." Now truth is greater than the mind of man; otherwise the mind would be the judge of truth: whereas in fact it judges all things according to truth, and not according to its own measure. Therefore God alone is truth. Therefore there is no other truth but God.

Objection 2. Further, Anselm says (De Verit. xiv), that, "as is the relation of time to temporal things, so is that of truth to true things." But there is only one time for all temporal things. Therefore there is only one truth, by which all things are true.

On the contrary, it is written (Psalm 11:2), "Truths are decayed from among the children of men."

I answer that, In one sense truth, whereby all things are true, is one, and in another sense it is not. In proof of which we must consider that when anything is predicated of many things univocally, it is found in each of them according to its proper nature; as animal is found in each species of animal. But when anything is predicated of many things analogically, it is found in only one of them according to its proper nature, and from this one the rest are denominated. So healthiness is predicated of animal, of urine, and of medicine, not that health is only in the animal; but from the health of the animal, medicine is called healthy, in so far as it is the cause of health, and urine is called healthy, in so far as it indicates health. And although health is neither in medicine nor in urine, yet in either there is something whereby the one causes, and the other indicates health. Now we have said (1) that truth resides primarily in the intellect; and secondarily in things, according as they are related to the divine intellect. If therefore we speak of truth, as it exists in the intellect, according to its proper nature, then are there many truths in many created intellects; and even in one and the same intellect, according to the number of things known. Whence a gloss on Psalm 11:2, "Truths are decayed from among the children of men," says: "As from one man's face many likenesses are reflected in a mirror, so many truths are reflected from the one divine truth." But if we speak of truth as it is in things, then all things are true by one primary truth; to which each one is assimilated according to its own entity. And thus, although the essences or forms of things are many, yet the truth of the divine intellect is one, in conformity to which all things are said to be true.

Reply to Objection 1. The soul does not judge of things according to any kind of truth, but according to the primary truth, inasmuch as it is reflected in the soul, as in a mirror, by reason of the first principles of the understanding. It follows, therefore, that the primary truth is greater than the soul. And yet, even created truth, which resides in our intellect, is greater than the soul, not simply, but in a certain degree, in so far as it is its perfection; even as science may be said to be greater than the soul. Yet it is true that nothing subsisting is greater than the rational soul, except God.

Reply to Objection 2. The saying of Anselm is correct in so far as things are said to be true by their relation to the divine intellect.


18 Cf. ⇒ Ex 32; ⇒ 33: 12-17
19 ⇒ Ex 33:18-19.
20 ⇒ Ex 34:5-6; cf. ⇒ 34:9
21 ⇒ Ex 34:7
22 ⇒ Eph 2:4
23 Jn 8:28 (Greek).
24 Cf. ⇒ Is 44:6
25 ⇒ Ps 102:26-27
26 ⇒ Jas 1:17
27 ⇒ Ex 34:6
28 ⇒ Ps 138:2; cf. ⇒ Ps 85:11
29 ⇒ I Jn 1:5; ⇒ 4:8
30 ⇒ Ps 119:160
31 ⇒ 2 Sam 7:28
32 Cf. ⇒ Dt 7:9
33 Cf ⇒ Wis 13:1-9.
34 Cf ⇒ Ps 115:15; ⇒ Wis 7:17-21.
35 ⇒ Mal 2:6.
36 ⇒ Jn 18:37.
37 ⇒ I Jn 5:20; cf. ⇒ Jn 17:3.