Chapter 25 — That to know God is the end of every intelligent substance

Now, seeing that all creatures, even those that are devoid of reason, are directed to God as their last end, and that all reach this end insofar as they have some share of a likeness to him, (Cc. 17–22.) the intellectual creature attains to him in a special way, namely, by understanding him through its proper operation. Consequently, to understand God must be the end of the intelligent creature.

For, as we have shown above, (Ch. 17.) God is the end of each thing. Therefore, as far as it is possible to it, each thing intends to be united to God as its last end. Now a thing is more closely united to God by reaching in a way to the very substance of God—which happens when it knows something of the divine substance—than when it reaches to a divine likeness. Therefore, the intellectual substance tends to the knowledge of God as its last end.

Again. The operation proper to a thing is its end, for it is its second perfection, so that when a thing is well conditioned for its proper operation it is said to be efficient and good. Now understanding is the proper operation of the intellectual substance: consequently, it is its end. Therefore, whatever is most perfect in this operation is its last end, especially in those operations which are not directed to some product, such as understanding and sensation. And since operations of this kind take their species from their objects, by which also they are known, it follows that the more perfect the object of any such operation, the more perfect is the operation. Consequently, to understand the most perfect intelligible, God, is the most perfect in the genus of this operation which is to understand. Therefore, to know God by an act of intelligence is the last end of every intellectual substance.

Someone, however, might say that the last end of an intellectual substance consists indeed in understanding the best intelligible, but that what is the best intelligible for this or that intellectual substance is not simply the best intelligible; and that the higher the intellectual substance, the higher is its best intelligible. So that perhaps the supreme intellectual substance has for its best intelligible that which is best simply, and its happiness will consist in understanding God; but the happiness of any lower intellectual substance will consist in understanding some lower intelligible (which, however, will be the highest thing understood by that substance). Especially would it seem not to be in the power of the human intellect to understand that which is simply the best intelligible on account of its weakness, for it is as much adapted for knowing the supreme intelligible as the owl’s eye for seeing the sun. (Metaphysics 1.1.)

Nevertheless, it is evident that the end of any intellectual substance, even the lowest, is to understand God. For it has been shown above (Ch. 17.) that God is the last end towards which all things tend. And the human intellect, although the lowest in the order of intelligent substances, is superior to all that are devoid of understanding. Since, then, a more exalted substance has not a less exalted end, God will be the end also of the human intelligence. Now every intelligent being attains to its last end by understanding it, as we have proved. Therefore, the human intellect attains to God as its end by understanding him.

Again. Just as things devoid of intelligence tend to God as their end by way of assimilation, so do intelligent substances by way of knowledge, as clearly appears from what has been said. Now, although things devoid of reason tend towards a likeness to their proximate causes, the intention of nature does not rest there, but has for its end a likeness to the highest good, as we have proved, (Ch. 19.) although they are able to attain to this likeness in a most imperfect manner. Therefore, however little be the knowledge of God to which the intellect is able to attain, this will be the intellect’s last end, rather than the perfect knowledge of lower intelligibles.

Moreover. Everything desires its last end most of all. Now, although it can grasp but little about them, the human intellect desires, loves, and enjoys the knowledge of divine things more than the perfect knowledge which it has of the lower world. Therefore, man’s last end is to understand God in some way or other.

Further. Everything tends to a divine likeness as its own end. Therefore, a thing’s last end is that whereby it is most of all like unto God. Now the intellectual creature is especially likened to God in that it is intellectual, since this likeness belongs to it above other creatures, and includes all other likenesses. And in this particular kind of likeness it is more like God in understanding actually than in understanding habitually or potentially, because God is always actually understanding, as we proved in the first book. (Ch. 56.) And in understanding actually he is especially like God in understanding God, because by understanding himself God understands all other things, as we proved in the first book. (Ch. 49.) Therefore, the last end of every intelligent substance is to understand God.

Again. That which is lovable only on account of another is for the sake of that which is lovable for its own sake alone, because we cannot go on indefinitely in the appetite of nature, since then nature’s desire would be in vain: for it is impossible to pass through an infinite number of things. Now all practical sciences, arts, and powers are lovable only for the sake of something else, since their end is not knowledge, but operation. But speculative sciences are lovable for their own sake, for their end is knowledge itself.

Nor can we find any action in connection with man that is not directed to some other end, with the exception of speculative consideration. For even playful actions, which would seem to be done without any purpose, have some end due to them, namely, that the mind may be relaxed, and that we may afterwards become more fit for studious occupations. Otherwise, if play were desirable for its own sake, we should always have to be playing, and this is unreasonable. Accordingly, practical art is directed to speculative art, and again every human operation to intellectual speculation as its end.

Now, in all sciences and arts that are mutually subordinate, the last end apparently belongs to the one from which others take their rules and principles: thus the art of sailing, to which belongs the ship’s end (namely, its use), provides rules and principles to the art of ship-building. And such is the relation of metaphysics to other speculative sciences, for all others depend on it since they derive their principles from it, and are directed by it in defending those principles: moreover, metaphysics is wholly directed to God as its last end (hence it is called the divine science). (1 Metaphysics 1.2.) Therefore, the knowledge of God is the last end of all human knowledge and actions.

Furthermore. In all mutually subordinate agents and movers, the end of the first agent must be the end of all, even as the end of the commander in chief is the end of all who are soldiering under him. Now of all the parts of man, the intellect is the highest mover, for it moves the appetite by proposing its object to it. The intellective appetite, or will, moves the sensitive appetites (namely, the irascible and concupiscible), so that we do not obey the concupiscence unless the will command; when the will consents, the sensitive appetite moves the body. Therefore, the end of the intellect is the end of all human actions. Now the intellect’s end and good are the true, (Ethics 6.2.) and its last end is the first truth. Therefore, the last end of all man and of all his deeds and desires is to know the first truth, namely God.

Moreover. Man has a natural desire to know the causes of whatever he sees. Hence, through wondering at things with hidden causes, men first began to philosophize, and when they had discovered the cause they were at rest. (Metaphysics 1.2.) Nor do they cease inquiring until they come to the first cause; and then do we consider ourselves to know perfectly when we know the first cause. (Metaphysics 1.3.) Therefore, man naturally desires to know the first cause as his last end. But God is the first cause of all. Therefore, man’s last end is to know God.

Besides. Man naturally desires to know the cause of any known effect. Now the human intellect knows universal being. Therefore, it naturally desires to know its cause, which is God alone, as we proved in the second book. (Ch. 15.) Now one has not attained to one’s last end until the natural desire is at rest. Therefore, the knowledge of any intelligible object is not enough for man’s happiness, which is his last end, unless he know God also, which knowledge, as his last end, terminates his natural desire. Therefore, this very knowledge of God is man’s last end.

Further. A body that tends by its natural appetite to its place is moved all the more vehemently and rapidly as it approaches nearer to its end. Hence Aristotle proves (On the Heavens 1.8, 277a14–33.) that a natural straight movement cannot be towards an indefinite point, because it would not be more moved afterwards than before. Hence that which tends more vehemently to a thing afterwards than before is not moved towards an indefinite point but towards something fixed. Now this we find in the desire of knowledge, for the more one knows, the greater one’s desire to know. Consequently, man’s natural desire in knowledge tends to a definite end. This can be no other but the highest thing knowable, which is God. Therefore, the knowledge of God is man’s last end.

Now the last end of man and of any intelligent substance is called happiness or beatitude: it is this that every intelligent substance desires as its last end, and for its own sake alone. Therefore, the last beatitude or happiness of any intelligent substance is to know God.

Hence it is said: Blessed are the pure in heart, for they shall see God (Matt 5:8); and: This is eternal life, that they know thee the only true God (John 17:3).

Aristotle agrees with this statement when he says that man’s ultimate happiness is contemplative, in regard to his contemplating the highest object of contemplation. (Nicomachean Ethics 10.7.)