possible purpose are in fact infinitely numerous. All sciences have
a practical part, consisting of problems expressing that some end is
possible for us and of imperatives directing how it may be attained.
These may, therefore, be called in general imperatives of skill.
Here there is no question whether the end is rational and good, but
only what one must do in order to attain it. The precepts for the
physician to make his patient thoroughly healthy, and for a poisoner
to ensure certain death, are of equal value in this respect, that each
serves to effect its purpose perfectly. Since in early youth it cannot
be known what ends are likely to occur to us in the course of life,
parents seek to have their children taught a great many things, and
provide for their skill in the use of means for all sorts of arbitrary
ends, of none of which can they determine whether it may not perhaps
hereafter be an object to their pupil, but which it is at all events
possible that he might aim at; and this anxiety is so great that
they commonly neglect to form and correct their judgement on the value
of the things which may be chosen as ends.

There is one end, however, which may be assumed to be actually
such to all rational beings (so far as imperatives apply to them,
viz., as dependent beings), and, therefore, one purpose which they not
merely may have, but which we may with certainty assume that they
all actually have by a natural necessity, and this is happiness. The
hypothetical imperative which expresses the practical necessity of
an action as means to the advancement of happiness is assertorial.
We are not to present it as necessary for an uncertain and merely
possible purpose, but for a purpose which we may presuppose with
certainty and a priori in every man, because it belongs to his
being. Now skill in the choice of means to his own greatest well-being
may be called prudence, * in the narrowest sense. And thus the