Summa Theologica, Part I-II (Pars Prima Secundae)

Since, as Damascene states (De Fide Orth. ii, 12), man is said to be made in God's image, in so far as the image implies "an intelligent being endowed with free-will and self-movement": now that we have treated of the exemplar, i.e. God, and of those things which came forth from the power of God in accordance with His will; it remains for us to treat of His image, i.e. man, inasmuch as he too is the principle of his actions, as having free-will and control of his actions.

OF MAN'S LAST END (In Eight Articles)

In this matter we shall consider first the last end of human life; and secondly, those things by means of which man may advance towards this end, or stray from the path: for the end is the rule of whatever is ordained to the end. And since the last end of human life is stated to be happiness, we must consider (1) the last end in general; (2) happiness.

Under the first head there are eight points of inquiry:

(1) Whether it belongs to man to act for an end?

(2) Whether this is proper to the rational nature?

(3) Whether a man's actions are specified by their end?

(4) Whether there is any last end of human life?

(5) Whether one man can have several last ends?

(6) Whether man ordains all to the last end?

(7) Whether all men have the same last end?

(8) Whether all other creatures concur with man in that last end?

FIRST ARTICLE [I-II, Q. 1, Art. 1]

Whether It Belongs to Man to Act for an End?

Objection 1: It would seem that it does not belong to man to act for an end. For a cause is naturally first. But an end, in its very name, implies something that is last. Therefore an end is not a cause. But that for which a man acts, is the cause of his action; since this preposition "for" indicates a relation of causality. Therefore it does not belong to man to act for an end.

Obj. 2: Further, that which is itself the last end is not for an end. But in some cases the last end is an action, as the Philosopher states (Ethic. i, 1). Therefore man does not do everything for an end.

Obj. 3: Further, then does a man seem to act for an end, when he acts deliberately. But man does many things without deliberation, sometimes not even thinking of what he is doing; for instance when one moves one's foot or hand, or scratches one's beard, while intent on something else. Therefore man does not do everything for an end.

On the contrary, All things contained in a genus are derived from the principle of that genus. Now the end is the principle in human operations, as the Philosopher states (Phys. ii, 9). Therefore it belongs to man to do everything for an end.

I answer that, Of actions done by man those alone are properly called "human," which are proper to man as man. Now man differs from irrational animals in this, that he is master of his actions. Wherefore those actions alone are properly called human, of which man is master. Now man is master of his actions through his reason and will; whence, too, the free-will is defined as "the faculty and will of reason." Therefore those actions are properly called human which proceed from a deliberate will. And if any other actions are found in man, they can be called actions "of a man," but not properly "human" actions, since they are not proper to man as man. Now it is clear that whatever actions proceed from a power, are caused by that power in accordance with the nature of its object. But the object of the will is the end and the good. Therefore all human actions must be for an end.

Reply Obj. 1: Although the end be last in the order of execution, yet it is first in the order of the agent's intention. And it is this way that it is a cause.

Reply Obj. 2: If any human action be the last end, it must be voluntary, else it would not be human, as stated above. Now an action is voluntary in one of two ways: first, because it is commanded by the will, e.g. to walk, or to speak; secondly, because it is elicited by the will, for instance the very act of willing. Now it is impossible for the very act elicited by the will to be the last end. For the object of the will is the end, just as the object of sight is color: wherefore just as the first visible cannot be the act of seeing, because every act of seeing is directed to a visible object; so the first appetible, i.e. the end, cannot be the very act of willing. Consequently it follows that if a human action be the last end, it must be an action commanded by the will: so that there, some action of man, at least the act of willing, is for the end. Therefore whatever a man does, it is true to say that man acts for an end, even when he does that action in which the last end consists.

Reply Obj. 3: Such like actions are not properly human actions; since they do not proceed from deliberation of the reason, which is the proper principle of human actions. Therefore they have indeed an imaginary end, but not one that is fixed by reason.

SECOND ARTICLE [I-II, Q. 1, Art. 2]

Whether It Is Proper to the Rational Nature to Act for an End?

Objection 1: It would seem that it is proper to the rational nature to act for an end. For man, to whom it belongs to act for an end, never acts for an unknown end. On the other hand, there are many things that have no knowledge of an end; either because they are altogether without knowledge, as insensible creatures: or because they do not apprehend the idea of an end as such, as irrational animals. Therefore it seems proper to the rational nature to act for an end.

Obj. 2: Further, to act for an end is to order one's action to an end. But this is the work of reason. Therefore it does not belong to things that lack reason.

Obj. 3: Further, the good and the end is the object of the will. But "the will is in the reason" (De Anima iii, 9). Therefore to act for an end belongs to none but a rational nature.

On the contrary, The Philosopher proves (Phys. ii, 5) that "not only mind but also nature acts for an end."

I answer that, Every agent, of necessity, acts for an end. For if, in a number of causes ordained to one another, the first be removed, the others must, of necessity, be removed also. Now the first of all causes is the final cause. The reason of which is that matter does not receive form, save in so far as it is moved by an agent; for nothing reduces itself from potentiality to act. But an agent does not move except out of intention for an end. For if the agent were not determinate to some particular effect, it would not do one thing rather than another: consequently in order that it produce a determinate effect, it must, of necessity, be determined to some certain one, which has the nature of an end. And just as this determination is effected, in the rational nature, by the "rational appetite," which is called the will; so, in other things, it is caused by their natural inclination, which is called the "natural appetite."

Nevertheless it must be observed that a thing tends to an end, by its action or movement, in two ways: first, as a thing, moving itself to the end, as man; secondly, as a thing moved by another to the end, as an arrow tends to a determinate end through being moved by the archer who directs his action to the end. Therefore those things that are possessed of reason, move themselves to an end; because they have dominion over their actions through their free-will, which is the "faculty of will and reason." But those things that lack reason tend to an end, by natural inclination, as being moved by another and not by themselves; since they do not know the nature of an end as such, and consequently cannot ordain anything to an end, but can be ordained to an end only by another. For the entire irrational nature is in comparison to God as an instrument to the principal agent, as stated above (I, Q. 22, A. 2, ad 4; Q. 103, A. 1, ad 3). Consequently it is proper to the rational nature to tend to an end, as directing (agens) and leading itself to the end: whereas it is proper to the irrational nature to tend to an end, as directed or led by another, whether it apprehend the end, as do irrational animals, or do not apprehend it, as is the case of those things which are altogether void of knowledge.

Reply Obj. 1: When a man of himself acts for an end, he knows the end: but when he is directed or led by another, for instance, when he acts at another's command, or when he is moved under another's compulsion, it is not necessary that he should know the end. And it is thus with irrational creatures.

Reply Obj. 2: To ordain towards an end belongs to that which directs itself to an end: whereas to be ordained to an end belongs to that which is directed by another to an end. And this can belong to an irrational nature, but owing to some one possessed of reason. Reply Obj. 3: The object of the will is the end and the good in universal. Consequently there can be no will in those things that lack reason and intellect, since they cannot apprehend the universal; but they have a natural appetite or a sensitive appetite, determinate to some particular good. Now it is clear that particular causes are moved by a universal cause: thus the governor of a city, who intends the common good, moves, by his command, all the particular departments of the city. Consequently all things that lack reason are, of necessity, moved to their particular ends by some rational will which extends to the universal good, namely by the Divine will.

THIRD ARTICLE [I-II, Q. 1, Art. 3]

Whether Human Acts Are Specified by Their End?

Objection 1: It would seem that human acts are not specified by their end. For the end is an extrinsic cause. But everything is specified by an intrinsic principle. Therefore human acts are not specified by their end.

Obj. 2: Further, that which gives a thing its species should exist before it. But the end comes into existence afterwards. Therefore a human act does not derive its species from the end.