man merely as a mean, without the latter containing at the same time
the end in himself. For he whom I propose by such a promise to use for
my own purposes cannot possibly assent to my mode of acting towards
him and, therefore, cannot himself contain the end of this action.
This violation of the principle of humanity in other men is more
obvious if we take in examples of attacks on the freedom and
property of others. For then it is clear that he who transgresses
the rights of men intends to use the person of others merely as a
means, without considering that as rational beings they ought always
to be esteemed also as ends, that is, as beings who must be capable of
containing in themselves the end of the very same action. *



* Let it not be thought that the common "quod tibi non vis fieri,
etc." could serve here as the rule or principle. For it is only a
deduction from the former, though with several limitations; it
cannot be a universal law, for it does not contain the principle of
duties to oneself, nor of the duties of benevolence to others (for
many a one would gladly consent that others should not benefit him,
provided only that he might be excused from showing benevolence to
them), nor finally that of duties of strict obligation to one another,
for on this principle the criminal might argue against the judge who
punishes him, and so on.



Thirdly, as regards contingent (meritorious) duties to oneself: It
is not enough that the action does not violate humanity in our own
person as an end in itself, it must also harmonize with it. Now