Commentaria in Summam contra Gentiles, Liber II

As to the second principal question, namely what is the true cause of the distinction of things ¹, the following conclusion is laid down: The cause of the distinction of things was God's own intention, as willing to give the creature that perfection which it was possible for it to have. And this speaks of essential perfection.

I. It is proved first. God is the most perfect agent. Therefore it belonged to him to imprint his likeness in created things most perfectly, insofar as it befits created nature. Therefore there had to be multiplicity and variety in created things. — The first consequence is proved. Because the more perfect an agent is, the more perfectly does it impress its likeness upon its effect, according to the capacity of the effect. — The second is also proved. Because created things cannot attain a perfect likeness of God through one single species of creature: since a creature cannot equal divine perfection, because God is a cause exceeding his effect.

It must be noted that this argument, and all the following ones, proceed on the supposition that God willed to produce this universe and to communicate His likeness to it in a certain determinate manner, and according to the perfection congruent with that universe. For given this supposition, it was fitting that He should impress His likeness upon the universe and communicate to it His perfection, insofar as the universe itself was capable of receiving it.

II. Second. There would not be a perfect likeness of God in the universe, insofar as the universe is capable of receiving it, if there were only one grade of all beings. Therefore, etc. — The consequence is proved by comparing active power to matter: namely, because if an agent can produce several effects and produces only one of them, its power is not reduced to act as completely as it would be if it produced many. But through the fact that active power is reduced to act, the effect receives a likeness of the agent.

Note that the intention of reason is not that God must do all things which He can do absolutely, but all things which He can do pertaining to the essential perfection of the universe which He intends.

Third. A created thing approaches God's likeness more perfectly if it is not only good in itself but also able to act toward the good of others, as is evident in the case of the luminous in relation to the sun. Therefore there must be plurality and inequality among creatures. — The consequence is proved. Because acting toward the good of another requires plurality and inequality, since the agent is other than the patient and more honorable than it.

It must be noted that this discourse concerns not only the univocal agent but also the equivocal agent. For if we were speaking of a merely univocal agent, that which is to act would not argue an inequality according to species, such as the argument intends to conclude, but only a material distinction.

III. Fourth. It belongs to the highest good to make what is better, namely in the effect that it intends. Therefore it was fitting that it should make many grades of creatures. — The consequence is evident. For many goods are better than one finite good.

Note first that Saint Thomas added finite: because with one infinite good, many finite goods are not better.

Note secondly, from the teaching of St. Thomas in Quaestt. de Malo, q. xvi, a. 1, ad 13, that this proposition holds true if the individual items are of one order, namely both the one and those many: for instance, many gold coins are better than one gold coin. But it does not hold when the many goods are of an order inferior to that one good.

But, although it is not taken in this sense here, the exposition itself nevertheless makes it clear that it also has truth in things of different orders, when several include that one thing within themselves. For this reason, several things of one order are better than a single one of that order, because they contain it and something more. Similarly, therefore, several things of different orders are better than a single one of them alone, because they include it and add something besides. Hence St. Thomas proves that proposition, because they have this and still more. It is therefore universally true when that one thing is contained among those several: namely, if all are finite.

IV. Fifth. A multitude of species adds more to the goodness of the universe than a multitude of individuals within one species. Therefore, the perfection of the universe requires not only that there be many individuals, but also that there be diverse species of things. — The antecedent is proved. Because the goodness of a species exceeds the goodness of an individual, namely of the material individual, where the goodness of the species is distinguished intrinsically from the goodness of the individual. This is evident: because the species is related to the individual as the formal to the material.

Sixth. The divine intellect understands many things, namely those pertaining to the perfection of the universe. Therefore it represents itself more perfectly if it produces several creatures of diverse grades than if it had produced only one. Therefore etc. — The consequence is proved. Because every agent acting through intellect represents the species of its intellect in the thing made.

But a doubt arises. For, if an agent acting through intellect represents the species of its intellect in the thing made, it follows that God produces only one thing and not many: because the species of his intellect is only one, namely the divine essence.

It is answered that it is one materially, but formally it is many, insofar as it is understood as the proper ratio of many things and has the ratio of many ideas.

Seventh. The good of the order of diverse things is better than any of those ordered things taken by itself, since it is formal with respect to the singulars. Therefore it ought to exist in things. Therefore there ought to be inequality in things. — The first inference is proved: because the work of the highest good craftsman ought not to lack the highest perfection. — The second is also proved: because, if inequality were removed, that good would not exist.

It must be noted that, when it is said that the good of the order of diverse things is better than any of the things ordered, this is understood not of the relation itself considered in itself—for a relation is of the least entity, and consequently of the least goodness—but of the very extremes of the order insofar as they are ordered. — In the same way is to be understood what is said at the end of the chapter: namely, that the order of the universe is the last and most noble perfection in things.

Concerning that proposition, that such an order would not exist without inequality, a doubt is raised. For among the divine Persons there is order. And yet there is no inequality there.

It is said that St. Thomas here speaks of the order of prior and posterior, but not of the order of origin alone, such as is found among the divine Persons.

This is confirmed by Genesis 1, where it is said, "And God saw all that He had made," etc.