i.e., to possible universal legislation through its maxims.  Actions that can co-exist with this autonomy are allowed; all others are not.  A will, whose maxims necessarily accord with the laws of Autonomy, is holy, or absolutely good; the dependence of a will not thus absolutely good is Obligation.  The objective necessity of an action from obligation is Duty.  Subjection to law is not the only element in duty; the fact of the law being self-imposed gives Dignity.

The Autonomy of the will is its being a law to itself, without respect to the objects of volition; the principle of autonomy is to choose only in such a way as that the maxims of choice are conceived at the same time as a universal law.  This rule cannot be proved analytically to be an Imperative, absolutely binding on every will; as a synthetic proposition it requires, besides a knowledge of the objects, a critique of the subject, i.e., pure practical Reason, before, in its apodeictic character, it can be proved completely a priori.  Still the mere analysis of moral conceptions has sufficed to prove it the sole principle of morals, because this principle is seen to be a categorical Imperative, and a categorical Imperative enjoins neither more nor less than this Autonomy.  If, then, Autonomy of Will is the supreme principle, Heteronomy is the source of all ungenuine principles, of Morality.  Heteronomy is whenever the Will does not give itself laws, but some object, in relation to the Will, gives them.  There is then never more than a hypothetical Imperative:  I am to do something because I wish something else.

There follows a division and criticism of the various possible principles of morality that can be set up on the assumption of Heteronomy, and that have been put forward by human Reason in default of the required Critique of its pure use.  Such, are either Empirical or Rational.  The Empirical, embodying the principle of Happiness, are founded on (1) physical or (2) moral feeling; the Rational, embodying the principle of perfection, on (1) the rational conception of it as a possible result, or (2) the conception of an independent perfection (the Will of God), as the determining cause of the will.  The Empirical principles are altogether to be rejected, because they can give no universal law for all rational beings; of the Rational principles, the first, though setting up an empty and indefinite conception, has the merit of at least making an appeal from sense to pure reason.  But the fatal objection to all four is their implying Heteronomy; no imperative founded on them can utter moral, i.e., categorical commands.