makes the law in itself the spring.

  But just for or reason, those duties also must be reckoned as of
indeterminate obligation, in respect of which there exists a
subjective principle which ethically rewards them; or to bring them as
near as possible to the notion of a strict obligation, a principle
of susceptibility of this reward according to the law of virtue;
namely, a moral pleasure which goes beyond mere satisfaction with
oneself (which may be merely negative), and of which it is proudly
said that in this consciousness virtue is its own reward.

  When this merit is a merit of the man in respect of other men of
promoting their natural ends, which are recognized as such by all
men (making their happiness his own), we might call it the sweet
merit, the consciousness of which creates a moral enjoyment in which
men are by sympathy inclined to revel; whereas the bitter merit of
promoting the true welfare of other men, even though they should not
recognize it as such (in the case of the unthankful and ungrateful),
has commonly no such reaction, but only produces a satisfaction with
one's self, although in the latter case this would be even greater.

  VIII. Exposition of the Duties of Virtue as Intermediate Duties

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

  Accordingly, this duty to estimate the worth of one's actions not
merely by their legality, but also by their morality (mental
disposition), is only of indeterminate obligation; the law does not
command this internal action in the human mind itself, but only the
maxim of the action, namely, that we should strive with all our
power that for all dutiful actions the thought of duty should be of
itself an adequate spring.

  (2) HAPPINESS OF OTHERS as an end which is also a duty

  (a) Physical Welfare. Benevolent wishes may be unlimited, for they
do not imply doing anything. But the case is more difficult with
benevolent action, especially when this is to be done, not from
friendly inclination (love) to others, but from duty, at the expense
of the sacrifice and mortification of many of our appetites. That this
beneficence is a duty results from this: that since our self-love
cannot be separated from the need to be loved by others (to obtain
help from them in case of necessity), we therefore make ourselves an
end for others; and this maxim can never be obligatory except by
having the specific character of a universal law, and consequently
by means of a will that we should also make others our ends. Hence the
happiness of others is an end that is also a duty.

  I am only bound then to sacrifice to others a part of my welfare
without hope of recompense: because it is my duty, and it is
impossible to assign definite limits how far that may go. Much depends