Kant argues that this is the only example of this sort and thus cannot be used as a general rule in defense of suicide. Kant's main argument against suicide is that people are entrusted with their lives, which have a uniquely inherent value. By killing oneself, a person dispenses with his humanity and makes himself into a thing to be treated like a beast. Kant also argues on more consequentialist grounds that if a person is capable of suicide, then he is capable of any crime. For autonomous suicides, though, the justification for intervention is less clear.
Intervention depends on whether paternalism in general is ever justified.
Mill's principle of liberty maintains that paternalism of this sort is never justified. According to Mill, we can only limit a person's conduct when it presents harm to others, irrespective of whether it presents harm to the agent himself. On this view, an initial suicide intervention may be justified, solely to establish whether the attempted suicide was autonomous or non-autonomous. If the attempt was autonomous, then no further intervention is justified. Decisions about some suicides are complicated in that they take place in hospitals or under the supervision of health care workers.