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.