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 pure morality in their mental disposition
may have belonged to each deed remains hidden even from themselves.