Only the lowest forms of slavery seek to control the thoughts of the slaves. Also see paragraph 12 for why it’s okay to eat meat.
1 First of all, then, the very way in which the intellectual creature was made, according as it is master of its acts, demands providential care whereby this creature may provide for itself, on its own behalf; while the way in which other things were created, things which have no dominion over their acts, shows this fact, that they are cared for, not for their own sake, but as subordinated to others.
That which is moved only by another being has the formal character of an instrument, but that which acts of itself has the essential character of a principal agent. Now, an instrument is not valued for its own sake, but as useful to a principal agent.
Hence it must be that all the careful work that is devoted to instruments is actually done for the sake of the agent, as for an end, but what is done for the principal agent, either by himself or by another, is for his own sake, because he is the principal agent. Therefore, intellectual creatures are so controlled by God, as objects of care for their own sakes; while other creatures are subordinated, as it were, to the rational creatures.
2 Again, one who holds dominion over his own acts is free in his activity, “for the free man is he who acts for his own sake.” But one who is acted upon by another, under necessity, is subject to slavery. So, every other creature is naturally subject to slavery; only the intellectual creature is by nature free.
Now, under every sort of government, provision is made for free men for their own sakes, but for slaves in such a way that they may be at the disposal of free men. And so, through divine providence provision is made for intellectual creatures on their own account, but for the remaining creatures for the sake of the intellectual ones.
Notes See the opening comment about slaves, which follows from this chapter, and in particular this paragraph.
3 Besides, whenever things are ordered to any end, and some of these things cannot attain the end through their own efforts, they must be subordinated to things which do achieve the end and which are ordered to the end for their own sakes. Thus, for instance, the end of an army is victory, and this the soldiers may achieve through their own act of fighting; that is why only soldiers are needed for their own sake in an army.
All others, who are assigned to different tasks—for instance, caring for the horses and supplying the weapons—are needed for the sake of the soldiers in the army. Now, from what has been seen earlier, it is established that God is the ultimate end of the whole of things; that an intellectual nature alone attains to Him in Himself, that is, by knowing and loving Him, as is evident from what has been said. Therefore, the intellectual nature is the only one that is required in the universe, for its own sake, while all others are for its sake.
4 Moreover, in any whole the principal parts are needed in themselves in order to constitute the whole, but the other parts are for the preservation or for some betterment of the principal ones. Now, of all the parts of the universe the more noble are intellectual creatures, since they come closer to the divine likeness. Therefore, intellectual creatures are governed by divine providence for their own sakes, while all others are for the intellectual ones.
5 Furthermore, it is evident that all parts are ordered to the perfection of the whole, since a whole does not exist for the sake of its parts, but, rather, the parts are for the whole.
Now, intellectual natures have a closer relationship to a whole than do other natures; indeed, each intellectual substance is, in a way, all things. For it may comprehend the entirety of being through its intellect; on the other hand, every other substance has only a particular share in being. Therefore, other substances may fittingly be providentially cared for by God for the sake of intellectual substances.
Notes In this is the necessity of nature, of essences. We are not parts: we are wholes.
6 Again, as a thing is acted upon in the course of nature, so is it disposed to action by its natural origin. Now, we see that things do go on in the course of nature in such a way that intellectual substance uses all others for itself: either for the perfecting of its understanding, since it contemplates the truth in them; or for the exercise of its power and the development of its knowledge, in the fashion of an artist who develops his artistic conception in bodily matter; or even for the support of his body which is united with the intellectual soul, as we see in the case of men. Therefore, it is clear that all things are divinely ruled by providence for the sake of intellectual substances.
7 Besides, what a man desires for its own sake is something which he always desires, for that which is, because of itself, always is. On the other hand, what a man desires for the sake of something else is not necessarily always desired; rather, the duration of the desire depends on that for which it is sought.
Now, the being of things flows forth from the divine will, as is shown in our earlier considerations. Therefore, those things which always exist among beings are willed by God for their own sake, while things which do not always exist are not for their own sake, but for the sake of something else. Now, intellectual substances come closest to existing always, for they are incorruptible. They are also immutable, excepting only their act of choice. Therefore, intellectual substances are governed for their own sake, in a sense, while others are for them.
Notes What a lovely argument! Seek what is permanent, seek Truth above all things.
8 Nor is what was shown in earlier arguments opposed to this, namely, that all parts of the universe are ordered to the perfection of the whole. For all parts are ordered to the perfection of the whole, inasmuch as one is made to serve another. Thus, in the human body it is apparent that the lungs contribute to the perfection of the body by rendering service to the heart; hence, it is not contradictory for the lungs to be for the sake of the heart, and also for the sake of the whole organism.
Likewise, it is not contradictory for some natures to be for the sake of the intellectual ones, and also for the sake of the perfection of the universe. For, in fact, if the things needed for the perfection of intellectual substance were lacking, the universe would not be complete.
9 Similarly, too, the foregoing is not opposed by the fact that individuals are for the sake of their proper species. Because they are ordered to their species, they possess a further ordination to intellectual nature. For a corruptible thing is not ordered to man for the sake of one individual man only, but for the sake of the whole human species. A corruptible thing could not be of use to the whole human species except by virtue of the thing’s entire species. Therefore, the order whereby corruptible things are ordered to man requires the subordination of individuals to their species.
10 However, we do not understand this statement, that intellectual substances are ordered for their own sake by divine providence, to mean that they are not more ultimately referred to God and to the perfection of the universe. In fact, they are said to be providentially managed for their own sake, and other things for their sake, in the sense that the goods which they receive through divine goodness are not given them for the advantage of another being, but the things given to other beings must be turned over to the use of intellectual substances in accord with divine providence.
11 Hence it is said in Deuteronomy (4:19): “Lest you see the sun and the moon and the other stars, and being deceived by error, you adore and serve them, which the Lord Your God created for the service of all the nations that are under heaven”; and again in the Psalm (8:8): “You subjected all things under his feet, all sheep and oxen, moreover the beasts of the field”; and in Wisdom (12:18) it is said: “You, being Master of power, judge with tranquility, and with great favor dispose of us.”
12 Through these considerations we refute the error of those who claim that it is a sin for man to kill brute animals. For animals are ordered to man’s use in the natural course of things, according to divine providence. Consequently, man uses them without any injustice, either by killing them or by employing them in any other way. For this reason, God said to Noah: “As the green herbs, I have delivered all flesh to you” (Gen. 9:3).
13 Indeed, if any statements are found in Sacred Scripture prohibiting the commission of an act of cruelty against brute animals, for instance, that one should not kill a bird accompanied by her young (Deut. 22:6), this is said either to turn the mind of man away from cruelty which might be used on other men, lest a person through practicing cruelty on brutes might go on to do the same to men; or because an injurious act committed on animals may lead to a temporal loss for some man, either for the agent or for another man; or there may be another interpretation of the text, as the Apostle (1 Cor. 9:9) explains it, in terms of “not muzzling the ox that treads the corn” (Deut. 25:4).
Notes I was warned once not to seek the company of those who kill chickens for this reason.