If suicide be supposed a crime, it is only cowardice can impel us to it. If it be no crime, both prudence and courage should engage us to rid ourselves at once of existence when it becomes a burden. It is the only way that we can then be useful to society, by setting an example which, if imitated, would preserve every one his chance for happiness in life, and would effectually free him from all danger or misery.

Philosophical Works (ed. 1854)