Date of this Version
Published in Transactions of the Nebraska Academy of Sciences, Volume 4 (1977).
Kant claims that his categorical imperative is a synthetic, a priori proposition, but he does not make clear what makes this proposition synthetic or a priori. In this essay it is argued that in Kant's view the proposition is synthetic a priori because it states a quasi-psychological fact: that rational beings are capable of acting from purely moral motives. This means that Kant is an "internalist" in W.D. Falk's sense.