Suicide and Homicide: Symmetries and Asymmetries in Kant’s Ethics

Kant formulated a secular argument against suicide’s permissibility based on what he regarded as the intrinsic value of humanity. In this paper, I first show that Kant’s moral framework entails that some types of suicide are morally permissible. Just as some homicides are morally permissible, according to Kant, so are suicides that are performed according to equivalent maxims. Intention, foreseeability, voluntariness, diminished responsibility, and mental capacity determine the moral characterization of the killing. I argue that a suicide taxonomy that differentiates types of suicide according to morally relevant criteria is compatible with Kantian ethics; it establishes that even where we hold a robust deontological sanctity of life position, we are not obligated to preserve the lives of people whose future life only offers profound suffering, and helping them to die may be justifiable if doing so honors their dignity and autonomy. Nevertheless, homicide and suicide are only weakly morally symmetrical in that even if a given suicide is morally impermissible, we do not normally have the right to prevent it forcibly, though this may be altered by juridical laws under some circumstances.