Were the disposal of human life so much reserved as the peculiar province of the almighty that it were an encroachment on his right for men to dispose of their own lives; it would be equally criminal to act for the preservation of life as for its destruction.
(…)
Do you imagine that I repine at providence or curse my creation, because I go out of life, and put a period to a being, which, were it to continue, would render me miserable? Far be such sentiments from me. I am only convinced of a matter of fact, which you yourself acknowledge possible, that human life may be unhappy, and that my existence, if farther prolonged, would become uneligible.

David Hume, On suicide, 1755