There is an often unspoken assumption at work in modern moral philosophy that morality is in important ways independent of social and political institutions. The intuitive idea is that whatever morality requires of us as individuals, it will be something that we are, as individuals, able to do, or able to do to the degree that we are virtuous or good. The assumed moral effect on us of political and social institutions is either, positively, to provide us with a set of benefits and burdens, the enjoyment and discharge of which may give us occasion for moral action, or negatively, if we hold political office or have some role with special responsibilities, to sometimes call for compromise with moral principle in order to do what is politically or institutionally necessary.

Kant's ethics has often seemed the exemplar of such a “separate spheres” conception of ethics and politics. Social and political institutions are presumed to arise as the necessary strategy for negotiating the natural lawlessness of collective life. Morality, by contrast, has its source in the a priori requirements of practical reason. It is thus both independent of and prior to politics. Moral action, accordingly, is a matter of bringing the will into conformity with a priori principles of practical reason. What calls for philosophy is the demonstration that this is possible.

The complement to this view of morality is a conception of the moral person as an autonomous individual acting under the burden of practical reason (in particular, the necessitation of the categorical imperative).