The Stoics viewed life as a party, and considered it the rational choice to leave the party (suicide) under certain conditions:
1. In service of one's country, i.e., an old friend shows up to the party and requires your services.
2. The arrival of rowdy revelers, i.e., tyrants who force us to say or do disgraceful things at the party.
3. Protracted illness that prevents the soul from the use of its tool, the body, i.e., spoilage of provisions for the party.
4. Poverty, i.e., scarceness of party provisions.
5. Madness, i.e., drunkenness at the party. In Buddhist terms, intoxicants lower one's inhibitions against doing no harm to others and, by default, the self, or in Stoic terms, lowering the inhibitions of practicing virtue. It would be a dangerous party for the wise and virtuous one who practiced moderation.
Source: Griffin, Miriam. "Philosophy, Cato, and Roman Suicide I," Greece and Rome, vol. 33, no. 1, 1986, pp. 64-77. Original source cited by Griffin, Stoicorum Veterum Fragmenta, a 1903-1905 collection by Hans von Arnim of fragments and testimony of the earlier Stoics.
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Gautama Buddha also had no problem with suicide. When one of his disciples suicided due to an illness, Gautama claimed the disciple had released attachment to life and had attained enlightenment.