A commitment to the thesis of the autonomy of reason can be located across various phases of German Idealism. Initiated in Kant's critical work, it developed diverse conceptualisations and functions in the philosophy of Fichte's Jena period, early Schelling and, arguably, all of Hegel's mature writings. For Kant the self-governance of reason was to mean, at the practical level, that rational agents could determine themselves through reason alone. To do so they would endorse principles for action, these principles taking the form of a law compelling for all rational beings. As materially pure, universal laws, practical principles were valid independently of the normative authority of existing sociocultural practice and of the pathological and wholly subjective preferences of any given empirical agent. The rational agent, through the use of autonomous reason, could both identify what a rational will should will and be at the same time moved to act upon what it wills. Kant's theory of reason offered a framework within which practical reason itself could be defended, and theories that privileged sentiment, happiness or any other variety of affective motive were exposed as antithetical to moral legislation.

For Kant it was not only practical reason that was capable of autonomy, that is, of providing us with laws that are independent of empirical causality. The very practice of philosophy itself – of theoretical reason – was to be reconceived as an exercise of autonomous reason. Without reference to experience it was supposed to be possible for reason to identify its own capacities and limitations. It could establish the different kinds of governance reason brings to bear on the various regions of concern to it. The limit points of reason were revealed when reason recognised its own contradictoriness within particular domains. Philosophy, construed in this new form, might be considered as reason's own self-explication.