Abstract

Kant's Grundlegung zur Metaphysik der Sitten is popular as an introduction into his philosophy and into fundamental ethics in general. Its third chapter is, nevertheless, a notoriously difficult text. According to many interpreters, it raises questions rather than answering them. This article tries to answer some questions which often remain unclear even in the secondary literature: how is the logical structure of the chapter; what exactly is the synthetic character of the categorical imperative; how does freedom function as the third, connecting term in this synthesis; what is the relationship between questions concerning the possibility and the validity of the categorical imperative? In his own words, Kant wants to give here 'a deduction of the principle of morality' but also of the concept of freedom. The double use of the term 'deduction' needs an accurate interpretation. One thesis of the article is that the deduction of freedom must not be identified with the problematic deduction of the categorical imperative. The deduction of the concept of freedom has a more modest function within the proof of the possibility of the categorical imperative. This means that the question concerning the proof of its validity is still open; but the very idea that such a proof is neither possible nor necessary evokes already the notion of the factum der Vernunft