Philosophy, Department of


Date of this Version



Jarbuch für Recht und Ethik (1997) 5: 437-459.


Copyright 1997, Friedrich-Alexander-Universität Erlangen-Nürnberg. Used by permission.


I will consider Kant's claim that the categorical imperative (CI) is a synthetic a priori proposition. We know from the first Critique that such propositions are likely to be very important, but also difficult to justify. Kant says exactly the same things about the CI in the Grundlegung: the CI is difficult to justify2, but if we do not succeed in justifying it, morality may be a mere "phantom of the brain.',3 Though little has been written on this topic, a correct understanding of this claim is important to understanding Kant's views.