Kant: Rationality as Practical Reason

Practical reasoning must provide other persons with reasons for action. It must, consequently, refrain from all presuppositions that are not available to them. This observation offers an insight into what Kant meant by the concept of legislation that is made by moral subjects. In Kant's philosophy autonomy should not be interpreted as self-expression exercised by persons who make law. Instead it is a practice of adopting maxims or 'laws' that are in no way derivative or dependent on one's preferences. Practical reason imposes on practical maxims a certain modal demand which is to be found at the foundation of his criticism of heteronomy in ethics and which supports his arguments for various formulations of the categorical imperative to warrant its adequacy with respect to rationality, autonomy and obligation.