Commentaria in Summam contra Gentiles, Liber III

After St. Thomas has shown that the divine law orders man to the love of God, he consequently shows that it also orders him to faith ¹.

I. And he posits this conclusion: By the divine law men are bound to right faith.

It is proved first as follows. The beginning of spiritual love must be an intellectual vision. This is explained from the likeness of bodily loving. — But the vision of that spiritual intelligible ² who is God cannot be had by us except through faith. And especially according as our beatitude consists in the fruition of Him: for the reason that it exceeds natural reason. — Therefore etc.

For the evidence of this argument, it must be considered that, since it was shown above ³ that the divine law brings men to love according to its perfect state, that is, according as it was given in the time of grace, that must be understood of the love of God by which He is loved as the ultimate end of our beatitude. But to the knowledge of this we cannot ascend except through faith, by which we believe that God is the object of our ultimate beatitude. Therefore the divine law, which primarily brings us to the love of God, secondarily also brings us to right faith, without which we could not love God. And this is the foundation of this argument.

It should be noted further that love (amor) is properly spoken of in the sensitive appetite, although it is also transferred to the intellective appetite, as is held in III Sent., d. XXVII, q. II, a. 1; but dilectio is spoken of in the intellective appetite. Because, therefore, the love of a bodily thing belongs to the sensitive appetite in so far as it is such, but the love of a spiritual thing belongs to the will, St. Thomas called the love of a bodily thing amatio, by which is signified the going forth into the act of sensitive love; but the love of a spiritual thing he called dilectio.

It should also be observed, when it is said that the principle of bodily loving is the vision which is through the eye, either that St. Thomas is not speaking of bodily loving universally, but of a particular sort, namely that by which someone is inclined toward the thing seen; or by the name of vision through the eye he understands all sensitive apprehension. But he posits vision through the eye because through this especially men are led to love.

II. Secondly. The divine law orders man to this, that he be totally subject to God. Therefore etc. — The consequence is proved. Because just as man is subject to God in loving with respect to the will, so in believing with respect to the intellect. Not, however, by believing anything false: because by God, who is truth, nothing false can be proposed to man (namely, as to be believed).

2. But a doubt arises. For it seems that the divine law leads to believing something false. For when God commanded Abraham to kill his son ⁴, through this Abraham was led to believe that his son was to be killed by him. Which was nevertheless false. Therefore etc.

It is answered that through that precept Abraham was not led to believe that his son was to be killed by him except under this condition: unless the precept should be revoked. And this was true, not however false: for he was truly to be killed by him unless God had revoked the precept.

How, moreover, falsehood cannot underlie faith, St. Thomas shows in IIa IIae, q. I, a. 3; and III Sent., d. XXIV, q. I, a. 1 ⁵.

III. Thirdly. He who errs concerning God does not know God, but apprehends something in place of God. Therefore he who errs concerning God can neither love Him nor desire Him. But the divine law aims at this, that men love and desire God. Therefore etc.

The first consequence is proved. Because according as something is known, according to this it is loved and desired.

The antecedent, however, is proved from the difference between composite things and simple things. Because in composite things, he who errs concerning some one of the essential principles, even if he does not know the thing simpliciter, nevertheless knows it secundum quid, for example according to genus; but in simple things, of which sort God is, any error (namely, concerning essential matters) totally excludes the knowledge of the thing.

2. For the evidence of this argument, it must be considered first that it is common to all simple things that their essence is not composed of several parts. Therefore, although in created simple things genus and difference are taken in so far as in them esse differs from essence, according to closeness to which and remoteness those are taken, as was shown in the preceding sections ⁶; nevertheless in them diverse parts do not correspond to genus and difference, as happens in material things, in which genus is taken from matter and difference from form. Therefore one cannot err concerning their difference while the knowledge of them according to genus remains, so far as is on the part of the thing: because, the difference having been removed from them as to that which is in the thing, there does not remain anything of it from which the genus is taken, since both are taken from the same thing. Hence if anyone were to think that the intelligence moving the sphere of Saturn is a corporeal substance, in no way would he apprehend the very substance of the intelligence: because the genus itself of substance is not taken from something else belonging to its essence than its difference, which is incorporeal; and therefore, an error existing concerning its difference, there does not remain anything apprehended of it, on the part of the thing, that corresponds to its genus. For even if something of it then seems to be apprehended, because substance is apprehended of it, which is common to it and to others, this nevertheless is not true: because substance is not its genus except logically and according to the apprehension of reason, but not metaphysically and on the part of the thing.

3. It must be considered secondly that created simple substances differ from the first substance, which is most simple, in that in them there is something accidental; but in the first substance there is no accident, but whatever is in it is its essence. Therefore because, as is said here, knowledge of a thing stands together with error concerning the accidents of the thing, someone can err concerning the accidents of a created simple substance while his knowledge concerning substantial matters remains. But because in simple things error concerning one of the essential principles wholly takes away the knowledge of the thing, therefore every error concerning God, to whom all things are essential, totally takes away the knowledge of Him. For that reason St. Thomas says absolutely that whoever errs concerning God does not know Him.

IV. Fourthly. It belongs to the divine law to prohibit vices. Therefore also to exclude false opinions concerning God, and concerning those things which are of God. Therefore etc. — The consequence is proved. Because, since the good of the intellect is the true, false opinion in intelligible matters is related just as vice opposed to virtue in moral matters.

The conclusion is confirmed by the authority of the Apostle in Heb. XI, and Deut. ⁷ VI.

Through this, moreover, is excluded the error of those who say that it matters nothing to man's salvation by whatever faith he serves God.

It should be noted that the error adduced here is very well excluded from what has been said. For if right faith is intended by the divine law, and this very right faith is commanded of us: where right faith is not present, the divine law is not observed, and consequently salvation cannot be attained. It is clear, moreover, that not all faith is right, since one says things contrary to another. Therefore it is impossible that a man be saved in just any faith, but one can be saved only in the right one.