This leads to the concept of autonomy: Rationalism and Enlightenment emphasize human autonomy. The word “autonomy” is not used in the sense of arbitrariness, of man making himself, of man deciding about himself, in terms of his individual desires and arbitrary wilfulness. Autonomy is derived from the Greek autos and nomos (self-law). It does not say, “I am a law unto myself,” but says that the universal law of reason, which is the structure of reality, is in me, and there I must face it. This concept of autonomy is often falsified by theologians who say this is the misery of man, that he wants to be autonomous but would be dependent on God. Now this is poor theology and poor philosophy, if you say that, because you don’t know what you are talking about! Autonomy is the natural law given by God, present in the human mind, present in the structure of the world. Natural law means mostly, in all classical philosophy and theology, the law of reason, which is Divine law.
Now following this law as we find it in ourselves: this is autonomy. Therefore autonomy is always connected with the strong, almost emphatic, obedience to the law of reason, and is stronger than any religious idea opposed to anything arbitrary.
The adherents of autonomy in the Enlightenment are very much opposed to any arbitrariness which they call., for instance, the Divine grace. They wanted to emphasize man’s obedience to the natural law of his nature and the nature of the world.
The opposite concept is heteronomy. Arbitrariness is actually heteronomy; it is the opposite of autonomy! Arbitrariness is given in the moment in which fear or desire determines our actions, whether this fear is produced by God or by society or by one’s own weakness. For Kant, the heteronomy, the authoritarian attitude of the churches – and even of God, if He is seen in an heteronomous light – is arbitrariness. Arbitrariness is subjection to authority, if this authority is not confirmed by reason itself. And then it is arbitrariness, because you subject yourselves on, the basis of fear, anxiety and desire.