Thomas Aquinas

“ 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." ”

“ I answer that, It is impossible for one man's will to be directed at the same time to diverse things, as last ends. Three reasons may be assigned for this. First, because, since everything desires its own perfection, a man desires for his ultimate end, that which he desires as his perfect and crowning good. ”

“ And if he desire it, not as his perfect good, which is the last end, he must, of necessity, desire it as tending to the perfect good, because the beginning of anything is always ordained to its completion; as is clearly the case in effects both of nature and of art. Wherefore every beginning of perfection is ordained to complete perfection which is achieved through the last end. ”

“ Reply to Objection 1: Those who sin turn from that in which their last end really consists: but they do not turn away from the intention of the last end, which intention they mistakenly seek in other things. ”

“ 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. ”

“ Since, then, all things that can be desired by the will, belong, as such, to one genus, the last end must needs be one. And all the more because in every genus there is one first principle; and the last end has the nature of a first principle, as stated above. Now as the last end of man, simply as man, is to the whole human race, so is the last end of any individual man to that individual. Therefore, just as of all men there is naturally one last end, so the will of an individual man must be fixed on one last end. ”

“ 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. ”

“ It is possible, however, that an act which is one in respect of its natural species, be ordained to several ends of the will: thus this act "to kill a man," which is but one act in respect of its natural species, can be ordained, as to an end, to the safeguarding of justice, and to the satisfying of anger: the result being that there would be several acts in different species of morality: since in one way there will be an act of virtue, in another, an act of vice. ”

“ Further, man's last end is the object of the will. But the object of the will is the universal good, which is the end of all. Therefore other things, too, concur in man's last end.
On the contrary, man's last end is happiness ”

“ 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. ”

“ 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. ”

“ Further, the Philosopher says at the beginning of his Metaphysics 1, [2] that speculative science is sought for its own sake. Now it cannot be said that each speculative science is the last end. Therefore man does not desire all, whatsoever he desires, for the last end. ”

“ For a movement does not receive its species from that which is its terminus accidentally, but only from that which is its "per se" terminus. Now moral ends are accidental to a natural thing, and conversely the relation to a natural end is accidental to morality. ”

“ 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. ”

“ 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. ”

“ For since movements are, in a way, divided into action and passion, each of these receives its species from an act; action indeed from the act which is the principle of acting, and passion from the act which is the terminus of the movement. Wherefore heating, as an action, is nothing else than a certain movement proceeding from heat, while heating as a passion is nothing else than a movement towards heat: and it is the definition that shows the specific nature. ”

“ But, since the First Good diffuses itself according to the intellect, to which it is proper to flow forth into its effects according to a certain fixed form; it follows that there is a certain measure to the flow of good things from the First Good from Which all other goods share the power of diffusion. ”