Founder of a Metaphysics of Morals 287Kant's idea of autonomy, which he also calls the "supreme principle of
morality" and which is therefore the principle that the Groundwork sets out
to establish, amounts to the claim that we, as rational beings, are a law unto
ourselves, or that we are free to give ourselves our own laws.^48 To be sure,
the laws we give ourselves must be such that they can be valid for any ra¬
tional being. This does not take anything away from Kant's radical position
that no one — no priest, no king, no God - can give us moral laws or dic¬
tate morality to us. We are not just to be responsible for ourselves, we are
also to be masters of ourselves. Morality thus presupposes freedom.
It is for this reason that the concept of freedom becomes "the key of the
explanation of the autonomy of the will."^49 But freedom is just as enig¬
matic as the categorical imperative. It "cannot be proved as something real
in ourselves and in human nature."^50 "We must presuppose it if we want
to think of a being as rational and endowed with consciousness of his causal¬
ity with respect to actions, that is, with a will, and so we find that... we
must assign to every being endowed with reason and will this property of
determining himself to action under the idea of freedom."^51
Kant's reasoning is circular, and he knows it. He needs to presuppose
freedom to make the claim that the categorical imperative captures the
essence of morality. He also needs to presuppose that the categorical im¬
perative is the essence of morality in order to trace "the determinate con¬
cept of morality back to the idea of freedom."^52 Kant thinks he can solve
the problem, or at least mitigate it, by claiming that we take "a different
standpoint when by means of freedom we think ourselves as causes effi¬
cient a priori than when we represent ourselves in terms of our actions as
effects that we see before our eyes." From the first point of view, we be¬
long to an "intellectual world" of which we have "no further cognizance,"
that is, to the world of things in themselves.^53 From the second point of
view we belong to a world of appearances that Kant had delineated so
well in the Critique of Pure Reason to make room for faith. The Ground¬
work is therefore in an important sense nothing more than a further
spelling out of one of the articles of belief of the first Critique. It shows that
freedom as autonomy is "the supreme principle of morality." It also offers
the first exact statement of the categorical imperative. The Groundwork
does no more — but that in itself constitutes one of the greatest achievements
in the history of philosophy. Yet, by so doing, Kant placed philosophy in a
rather more "precarious position" than the one in which Garve (and Cicero)
had left it — arguing that "there is nothing in heaven or on earth upon
which it depends or is based."^54