Perfect Duties to Oneself as an Animal Being

This chapter considers the category of duties to oneself as an animal being: duties to avoid suicide and forms of self-mutilation, sexual self-abuse, and drunkenness and gluttony. Kant’s arguments for the claim that each of these types of action is morally wrong appeals to the “humanity formula” of his supreme principle of morality (the categorical imperative). Importantly, the role of teleology in some of Kant’s arguments is discussed and a distinction between ‘natural’ and ‘moral’ teleology is introduced. The chapter argues that while Kant mentions the natural purpose of one’s sexual powers in his argument against sexual self-abuse, his argument does not depend on it. However, as explained in later chapters, Kant’s ethics does rely on appeals to moral teleology, referring to the moral end of self-perfection.