But one may say: 'It is true that the last end of a subsistent intelligence consists in understanding the best intelligible object, still the best intelligible object, absolutely speaking, is not the best object for this or that subsistent intelligence; but the higher any subsistent intelligence is, the higher is its best intelligible object; and therefore the highest subsistent intelligence created has for its best intelligible object that which is best absolutely; hence its happiness will be in understanding God; but the happiness of a lower subsistent intelligence will be to understand some lower intelligible object, which is at the same time the highest of the objects that can be understood by it. And particularly it seems to be the lot of the human understanding, on account of its weakness, not to understand the absolutely best intelligible object: for in respect of the knowledge of that truth of which there is most to be known the human intellect is as the bat's eye to the sun.
Nevertheless it may be manifestly shown that the end of every subsistent intelligence, even the lowest, is to understand God. For (a) the final end of all beings, to which they tend, is God (Chap. XVIII. But the human understanding, however it be lowest in the order of subsistent intelligences, is nevertheless superior to all beings devoid of understanding. Since then the nobler substance has not the ignobler end, God Himself will be the end also of the human understanding. But every intelligent being gains its last end by understanding it. Therefore it is by understanding that the human intellect attains God as its end.
(c). Everything most of all desires its own last end. But the human mind is moved to more desire and love and delight over the knowledge of divine things, little as it can discern about them, than over the perfect knowledge that it has of the lowest things.*
(e). All sciences and arts and practical faculties are attractive only for the sake of something else: for in them the end is not knowledge but production of a work. But speculative sciences are attractive for their own sake, for their end is sheer knowledge. Nor is there found any action in human life, with the exception of speculative study, which is not directed to some other and further end. Even actions done in sport, which seem to be done in view of no end, have a due end, which is refreshment of mind, to enable us thereby to return stronger to serious occupations: otherwise we should play always, if play was sought for its own sake, which would be unbefitting.* Therefore the practical arts are ordained to the speculative, and all human activity has intellectual speculation for its end. In all due ordination of sciences and arts, the character of final end attaches to that science or art which issues precepts as master-builder to the rest: thus the art of navigation, to which belongs the management of a ship, lays down precepts for ship-building. In this relation Metaphysics (philosophia prima) stand to all speculative sciences. On metaphysics they all depend, and from that science they receive their principles and directions how to proceed against deniers of principles.* This first philosophy is wholly directed to the final end of the knowledge of God: hence it is called a divine science. The knowledge of God therefore is the final end of all human study and activity.
(f). In all series of agents and causes of change the end of the prime agent and mover must be the ultimate end of all, as the end of a general is the end of all the soldiers who serve under him. But among all the component parts of man we find the intellect to be the superior moving power: for the intellect moves the appetite, putting its object before it; and the intellectual appetite, or will, moves the sensible appetites, the irascible and concupiscible: hence we do not obey concupiscence except under the command of the will.* The sensitive appetite, crowned by the consent of the will, proceeds to move the body. The end therefore of the intellect is the end of all human actions. But the end and good of the intellect is truth; and consequently its last end is the first truth. The last end then of the whole man and of all his activities and desires is to know the first truth, which is God.
(g). There is a natural desire in all men of knowing the causes of the things that they see. It was through wonder at seeing things, the causes of which were unseen, that men first began to philosophise. Nor does enquiry cease until we arrive at the first cause: then we consider our knowledge perfect, when we know the first cause. Man then naturally desires so to know the first cause as his last end.* But the first cause is God; and the last end of man and of every subsistent intelligence, is called blessedness or happiness. To know God then is the blessedness and happiness of every subsistent intelligence.*
Hence it is said: This is eternal life, that they know thee, the only true God (John xvii, 3).
3.24 : That all things seek Good, even things devoid of Consciousness
3.26 : That Happiness does not consist in any Act of the Will