INTRODUCTION TO THE METAPHYSICAL ELEMENTS OF ETHICS
Ethics in ancient times signified moral philosophy (philosophia moralis) generally, which was also called the doctrine of duties. Subsequently it was found advisable to confine this name to a part of moral philosophy, namely, to the doctrine of duties which are not subject to external laws (for which in German the name Tugendlehre was found suitable). Thus the system of general deontology is divided into that of jurisprudence (jurisprudentia), which is capable of external laws, and of ethics, which is not thus capable, and we may let this division stand.
I. Exposition of the Conception of Ethics
The notion of duty is in itself already the notion of a constraint of the free elective will by the law; whether this constraint be an external one or be self-constraint. The moral imperative, by its categorical (the unconditional ought) announces this constraint, which therefore does not apply to all rational beings (for there may also be holy beings), but applies to men as rational physical beings who are unholy enough to be seduced by pleasure to the transgression of the moral law, although they themselves recognize its authority; and when they do obey it, to obey it unwillingly (with resistance of their inclination); and it is in this that the constraint properly consists. * Now, as man is a free (moral) being, the notion of duty can contain only self-constraint (by the idea of the law itself), when we look to the internal determination of the will (the spring), for thus only is it possible to combine that constraint (even if it were external) with the freedom of the elective will. The notion of duty then must be an ethical one.
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* Man, however, as at the same time a moral being, when he
considers himself objectively, which he is qualified to do
by his pure practical reason, (i.e. according to humanity in
his own person), finds himself holy enough to transgress the
law only unwillingly; for there is no man so depraved who in
this transgression would not feel a resistance and an
abhorrence of himself, so that he must put a force on
himself. It is impossible to explain the phenomenon that at
this parting of the ways (where the beautiful fable places
Hercules between virtue and sensuality) man shows more
propensity to obey inclination than the law. For, we can
only explain what happens by tracing it to a cause according
to physical laws; but then we should not be able to conceive
the elective will as free. Now this mutually opposed self-
constraint and the inevitability of it makes us recognize
the incomprehensible property of freedom.