Philosophical discussions of the morality of suicide have tended to focus on its justifiability from an agent’s point of view rather than on the justifiability of attempts by others to intervene so as to prevent it. This paper addresses questions of suicide intervention within a broadly Kantian perspective. In such a perspective, a chief task is to determine the motives underlying most suicidal behaviour. Kant wrongly characterizes this motive as one of self-love or the pursuit of happiness. Psychiatric and scientific evidence suggests that suicide is instead motivated by a nihilistic disenchantment with the possibility of happiness which, at its apex, results in the loss of the individual’s conception of her practical identity. Because of this, methods of intervention that appeal to agents’ happiness, while morally benign, will prove ineffective in forestalling suicide. At the same time, more aggressive methods violate the Kantian concern for autonomy. This apparent dilemma can be resolved by seeing suicide intervention as an action undertaken in non-ideal circumstances, where otherwise unjustified manipulation, coercion, or paternalism are morally permitted.