Commentaria in Summam contra Gentiles, Liber III

After St. Thomas has shown that all things act on account of something, he shows that the end of anything whatever is good¹.

I. And he argues first in this way. Every agent acts on account of good, as has been proved. Therefore, the good itself is the end. — The consequence is proved. For every agent is ordained to an end through its action: for either the operation itself is the end; or the end of the action is the end of the agent. Which is its good.

It must be observed that when an agent does not intend anything other beyond the operation itself, as happens in contemplation, the operation itself is the end. When, however, an agent intends something other beyond the operation itself, as when by building one intends a house or habitation; then that which is intended by the agent is the end both of the agent and of the action; of the agent, indeed, as intending to attain to it through its operation, but of the action as of that which is ordained to it. On account of this St. Thomas says that sometimes the end of the action is the end of the agent.

2. But a doubt arises. For sometimes an agent intends the good of another through its action: as when someone builds a house so that someone else may inhabit it. Therefore, it is false that, speaking universally, the end of the agent is its good.

It is answered in two ways. First, that the end of the agent, although it is sometimes something extrinsic, is nevertheless its good and perfection inasmuch as it is an agent, as is said in II Sent., d. xxxvii, art. ult.², because it moves it to act, and consequently reduces it to act; and also the operation has some perfection from the end itself.

It is answered secondly, from the teaching of St. Thomas, Prima, q. ciii, a. 2, ad 1 and 2, that the good of something is sometimes spoken of as that by which it is effected and actuated as a form, as health is the good of a healthy man; sometimes as operated through it, as a house is the good of the builder, or something of this sort; sometimes as had or possessed, as a purchased field is the good of the buyer; sometimes as represented by it, as Hercules is the good of an image that is made to represent him. And thus it is clear that the house or habitation is in some way the good of the builder, although it is something extrinsic to him. Whence the consequence is denied. For it stands together that the end of an agent is the good of someone else in one way, and is also in another way the good of the agent.

II. Secondly, it is argued. The appetite of anything whatever terminates at the good: as is evident from the definition of the good. Therefore, etc. — The consequence is proved. For the end of a thing is that at which its appetite terminates.

It must be observed concerning the antecedent and the proof of the consequence, that St. Thomas is speaking of the primary and per se termination of appetite. For as is said in Prima, q. xx, a. 1, the good is primarily and per se the object of the will, but evil secondarily and through another, namely, inasmuch as it is opposed to the good: for the appetite does not flee from any evil except because it is contrary to the good toward which it is inclined per se. And thus the appetite of a thing terminates at the good primarily and per se, although secondarily and through another it terminates at evil, by fleeing from it. — In like manner it must be understood what is assumed for the proof of the consequence. For the end of a thing is that at which appetite terminates primarily and per se.

Thirdly. The end of each thing is its perfection. Therefore, good. — The antecedent is proved. For each thing, if it lacks its proper perfection, is moved toward it, as far as is in itself, that is, unless it is impeded: but if it has it, it rests in it. Now this is the condition of an end.

Fourthly. Things that know an end are always ordained to the good as to an end: because the will is not borne toward anything except under the aspect of good, which is its object. Therefore, also things that do not know an end. And thus the end of all things is good. — The consequence is proved. Because things that know an end and things that do not know an end are ordained to the end in the same way, although they are moved to it in different ways.

III. Concerning what is said in this argument, two doubts arise. The first is concerning the proof of the antecedent. For the proof seems insufficient. For it had to be proved universally that things knowing an end are ordained to the good. And it is proved only concerning the will: when nevertheless even brutes, which do not have a will, know an end.

The second is concerning the proof of the consequence. For it seems contradictory that all things are ordained to the end in the same way, and yet are moved to it in different ways: for if they are moved to the end in different ways, it follows that they are not ordained to the end in the same way.

2. To the first, it is answered that by things that know an end, St. Thomas understands things that know the end under the aspect of an end, because they do not merely know that which is an end, but also the very aspect of an end: for these are the things that are properly said to be moved to an end per se. But such are only those that have intellect, as was shown above³, but not brutes. And because the will follows the intellect, therefore, while it is proved that the will is ordained to the good, it is proved universally that things knowing an end are ordained to the good.

3. To the second, it is said that the word in the same way does not import a similarity of order to the end, but expresses truth. For the sense is that it is just as true that things lacking knowledge are ordained and inclined to an end, as this is true concerning things having knowledge of an end. And it is like as if we were to say concerning Socrates having whiteness, on the supposition that Plato also is white, but has a more intense whiteness: In the same way Socrates is white and Plato, that is, It is just as true that Socrates is white, as it is true concerning Plato. But the objection proceeds as if it imported a similarity.

It can be answered secondly that it imports a similarity as to that from which the order and inclination proceed. For whether things know the end, as intellectual things; or do not know it, as naturally moved things; inclination and order follow knowledge. For the appetite of an end in things having knowledge follows the knowledge of the one desiring: but the appetite of one not having knowledge follows knowledge, not indeed of the one desiring, but of some other ordaining it to an end. Whence in II Physics⁴ it is said that the work of nature is the work of intelligence. And therefore it is very well argued that, if the end of one is good, the end of the other also is good: since in both cases such an ordination proceeds from knowledge. But although there is a similarity in this, it is not necessary, however, that there be a similarity as to the motion toward the end, such that, if one is moved to the end per se, the other also is moved per se. Whence there is no contradiction.