Our methodological approach in this paper consists of an examination of Kant's Lectures on Ethics as the laboratory where the concept of ethic formalism was forged. In our opinion, Kant's academic discurse on moral philosophy in this work contains many arguments included in the second Critique which reappear almost intact at the end of a complex process of catalysis induced by those same arguments.

However, the line of argument followed in Lectures on Ethics is no doubt the most important, because the order in which the problems appear offers certain clues to a better understanding of the sctructure of Critique of Practical Reason, as well as to the understanding of the complexity of the Kantian doctrine of Highest Good.

This interpretation explains to an extent, why the esample of promise was given such importance in the Groundwork (and other texts) since veracity is conceived in the Lectures as the matrix of a will, good in it self, and thus is demonstrated as an original value which rests upon Kant's instuition of categorical imperative.

On the other hand, we may see that, from the begining, Kant's God is to be found reclined in Procust's bed of morality, since His will, not being the source of moral law, must adopt it and adapt to it scrupulously.

Peer reviewed