Wealth consists not in having great possessions, but in having few wants ― Epictetus¹
Stoicism is a Greek philosophical school founded by Zeno of Citium, c. 300 BCE. The Stoics believed that mankind is superior to animals by virtue of our reason. The good life is lived in accord with nature; whereas evil is an unpleasant aspect of nature.
The Stoics felt it important to know about the existence of, and control one’s reaction to, evil. So thoughts and understanding are not enough. The superior person behaves right, which (apparently) makes him or her immune to suffering. This is a slightly different take on the well-known Christian doctrine, Be wise as serpents and harmless as doves.²
The Stoics saw the Greek gods in terms of cosmic forces, a view resembling a modern approach to mythology. The afterlife was generally not believed in. However, the Stoics did subscribe to an eternal return, an idea also mentioned in the works of Friedrich Nietzsche.
The philosopher Epictetus, the Roman statesman Seneca and Emporer Marcus Aurelius are usually regarded as Stoics. Wikipedia elaborates:
Later Stoics—such as Seneca and Epictetus—emphasized that, because “virtue is sufficient for happiness”, a sage was immune to misfortune. This belief is similar to the meaning of the phrase “stoic calm”, though the phrase does not include the “radical ethical” Stoic views that only a sage can be considered truly free, and that all moral corruptions are equally vicious.
From its founding, Stoic doctrine was popular with a following in Roman Greece and throughout the Roman Empire — including the Emperor Marcus Aurelius — until the closing of all pagan philosophy schools in 529 AD by order of the Emperor Justinian I, who perceived them as being at odds with Christian faith