A metaphysic of morals is therefore indispensably necessary, not merely for speculative reasons, in order to investigate the sources of the practical principles which are to be found a priori in our reason, but also because morals themselves are liable to all sorts of corruption, as long as we are without that clue and supreme canon by which to estimate them correctly.  For in order that an action should be morally good, it is not enough that it conform to the moral law, but it must also be done for the sake of the law, otherwise that conformity is only very contingent and uncertain; since a principle which is not moral, although it may now and then produce actions conformable to the law, will also often produce actions which contradict it.  Now it is only in a pure philosophy that we can look for the moral law in its purity and genuineness (and, in a practical matter, this is of the utmost consequence):  we must, therefore, begin with pure philosophy (metaphysic), and without it there cannot be any moral philosophy at all.  That which mingles these pure principles with the empirical does not deserve the name of philosophy (for what distinguishes philosophy from common rational knowledge is, that it treats in separate sciences what the latter only comprehends confusedly); much less does it deserve that of moral philosophy, since by this confusion it even spoils the purity of morals themselves, and counteracts its own end.

Let it not be thought, however, that what is here demanded is already extant in the propaedeutic prefixed by the celebrated Wolf [Footnote:  Johann Christian Von Wolf (1679-1728) was the author of treatises on philosophy, mathematics, &c., which were for a long time the standard text-books in the German Universities.  His philosophy was founded on that of Leibnitz.] to his moral philosophy, namely, his so-called general practical philosophy, and that, therefore, we have not to strike into an entirely new field.  Just because it was to be a general practical philosophy, it has not taken into consideration a will of any particular kind-say one which should be determined solely from a priori principles without any empirical motives, and which we might call a pure will, but volition in general, with all the actions and conditions which belong to it in this general signification.  By this it is distinguished from a metaphysic of morals, just as general logic, which treats of the acts and canons of thought in general, is distinguished from transcendental philosophy, which treats of the particular acts and canons of pure thought, i. e. that whose cognitions are altogether a priori.  For the metaphysic of morals has to examine the idea and the principles of a possible pure will, and not the acts and conditions of human volition generally, which for the most part are drawn from psychology.  It is true that moral laws and duty are spoken of in the general practical philosophy (contrary indeed to all fitness).  But this is no objection, for in this respect, also the