Commentaria in Summam contra Gentiles, Liber I

Assuming those things said in the first chapter about the wise man, St. Thomas sets out his purpose, saying that his intention is to manifest the truth of the Christian faith by eliminating contrary errors. The reason for this purpose is that, trusting in divine mercy, he intends to undertake the office of the wise man, which exceeds his own powers, namely to teach truth and exclude falsehood, as was shown above ¹

He assigns a twofold reason why the office of the wise man is undertaken ². The first is that among all the pursuits of men, the pursuit of wisdom is more perfect, more sublime, more useful, and more delightful. More perfect indeed, because through it a man already has some part of true beatitude, according to Ecclesiasticus 14: Blessed is the man who shall abide in wisdom. — More sublime, however, because through this a man especially approaches the divine likeness, which made all things in wisdom; and consequently he is joined to God through friendship, since likeness is a cause of love; hence it is said in Wisdom 7 that wisdom is an infinite treasure by which etc. — More useful indeed, because through wisdom one arrives at the kingdom of immortality, according to Wisdom 6: The desire of wisdom etc. — More delightful, however, because in Wisdom 8: her conversation has no bitterness nor etc.

II. For the clarification of these points, it must first be noted that, since beatitude consists in the contemplation of the divine truth and of the divine essence as it is in itself, when someone devotes himself to the pursuit of wisdom, he participates in some likeness of that supreme beatitude. Hence it is rightly said here that he already possesses some part of true beatitude.

It must be noted, secondly, from the doctrine of St. Thomas in II-II, q. 19, a. 7, that although wisdom among the philosophers is merely cognitive of the highest causes and consists absolutely in speculation alone, among theologians it is nevertheless not only cognitive but also directive of human life, which is directed not only by human reasons but also by divine reasons and rules, as is found in Augustine, XII de Trin. ³. Therefore one who devotes himself to the study of such wisdom is assimilated to God in a twofold way: first, with respect to the knowledge that God has of Himself; second, with respect to operation. For just as God knows Himself and made all things in wisdom, so the wise man both knows God and is directed in his works not only by human but also by divine rules. Hence it is well said here that man, through the study of wisdom, approaches the divine likeness.

It must be noted, third, that the saying of Saint Thomas, that through wisdom one arrives at the kingdom of immortality, can have a twofold reason. The first is because, as was said, wisdom causes friendship with God, through which we are advanced toward eternal beatitude. — The second, because the wise man, through the study of wisdom, is directed in right works, by which he is prepared for immortal life. For although those who devote themselves to human wisdom often fall away from virtue, those who nevertheless give their attention to divine wisdom, of which we speak, are insofar disposed to immortality, because they are directed in good works by wisdom according to divine rules.

A fourth point must be noted: that the reason why the pursuit of wisdom is said to be more delightful than all other human pursuits can be twofold. First, because, as Aristotle holds in Book XI of the De Animalibus ⁴, the lover takes more delight in a small grasp of the beloved than in a great grasp of other things. Second, because, as is said in the same place, the little we can understand about separate substances delights us more than whatever we have come to know about other things. Therefore far more delightful and pleasurable is the knowledge of God than of any other things whatsoever, especially when that knowledge draws one to the love of God.

III. The second reason why the wise man should take up the proposed task ⁵ is that, according to Hilary's opinion, he considers it his proper office that all his speech and thought should speak of God.

Next he excuses himself for why he does not proceed against each individual error. For he says he does this, first, because the errors of all are not known, so that from those things which are said arguments could be taken for destroying their errors. — Then, because some of them, such as the Mohammedans and the pagans, do not accept the authority of Scripture. Therefore one must have recourse to natural reason, to which all are compelled to assent; which, however, is deficient in divine matters. Where I note that, because our natural light stands as far below divine things as possible, it cannot by its own power rise perspicaciously to them. Hence there are certain errors concerning divine things which we cannot eliminate by effective argument. Therefore, when even such sowers of errors do not accept divine Scripture, they are rather to be passed over than attacked with ineffectual argument.

Finally, Saint Thomas adds that, while investigating some truth, he will at the same time show which errors are excluded by it, and how demonstrative truth accords with the Christian religion.