Looking back now on all previous attempts to discover the
principle of morality, we need not wonder why they all failed. It
was seen that man was bound to laws by duty, but it was not observed
that the laws to which he is subject are only those of his own giving,
though at the same time they are universal, and that he is only
bound to act in conformity with his own will; a will, however, which
is designed by nature to give universal laws. For when one has
conceived man only as subject to a law (no matter what), then this law
required some interest, either by way of attraction or constraint,
since it did not originate as a law from his own will, but this will
was according to a law obliged by something else to act in a certain
manner. Now by this necessary consequence all the labour spent in
finding a supreme principle of duty was irrevocably lost. For men
never elicited duty, but only a necessity of acting from a certain
interest. Whether this interest was private or otherwise, in any
case the imperative must be conditional and could not by any means
be capable of being a moral command. I will therefore call this the
principle of autonomy of the will, in contrast with every other
which I accordingly reckon as heteronomy.

The conception of the will of every rational being as one which must
consider itself as giving in all the maxims of its will universal
laws, so as to judge itself and its actions from this point of view-
this conception leads to another which depends on it and is very
fruitful, namely that of a kingdom of ends.

By a kingdom I understand the union of different rational beings
in a system by common laws. Now since it is by laws that ends are
determined as regards their universal validity, hence, if we