(1) OUR OWN PERFECTION as an end which is also a duty

(a) Physical perfection; that is, cultivation of all our faculties generally for the promotion of the ends set before us by reason. That this is a duty, and therefore an end in itself, and that the effort to effect this even without regard to the advantage that it secures us, is based, not on a conditional (pragmatic), but an unconditional (moral) imperative, may be seen from the following consideration. The power of proposing to ourselves an end is the characteristic of humanity (as distinguished from the brutes). With the end of humanity in our own person is therefore combined the rational will, and consequently the duty of deserving well of humanity by culture generally, by acquiring or advancing the power to carry out all sorts of possible ends, so far as this power is to be found in man; that is, it is a duty to cultivate the crude capacities of our nature, since it is by that cultivation that the animal is raised to man, therefore it is a duty in itself.

This duty, however, is merely ethical, that is, of indeterminate obligation. No principle of reason prescribes how far one must go in this effort (in enlarging or correcting his faculty of understanding, that is, in acquisition of knowledge or technical capacity); and besides the difference in the circumstances into which men may come makes the choice of the kind of employment for which he should cultivate his talent very arbitrary. Here, therefore, there is no law of reason for actions, but only for the maxim of actions, viz.: "Cultivate thy faculties of mind and body so as to be effective for all ends that may come in thy way, uncertain which of them may become thy own."

(b) Cultivation of Morality in ourselves. The greatest moral perfection of man is to do his duty, and that from duty (that the law be not only the rule but also the spring of his actions). Now at first sight this seems to be a strict obligation, and as if the principle of duty commanded not merely the legality of every action, but also the morality, i.e., the mental disposition, with the exactness and strictness of a law; but in fact the law commands even here only the maxim of the action, namely, that we should seek the ground of obligation, not in the sensible impulses (advantage or disadvantage), but wholly in the law; so that the action itself is not commanded. For it is not possible to man to see so far into the depth of his own heart that he could ever be thoroughly certain of the purity of his moral purpose and the sincerity of his mind even in one single action, although he has no doubt about the legality of it. Nay, often the weakness which deters a man from the risk of a crime is regarded by him as virtue (which gives the notion of strength). And how many there are who may have led a long blameless life, who are only fortunate in having escaped so many temptations. How much of the element of pur............