Those outside things which are commonly called good or bad, such as health and sickness, wealth and poverty, pleasure and pain, are to him indifferent, αδιαφορα. All these things are merely the sphere in which virtue may act.
 Marcus Aurelius, Meditations (c. 170 - 180). copy citation

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Author Marcus Aurelius
Source Meditations
Topic wealth poverty
Date c. 170 - 180
Language English
Reference
Note Translated by Meric Casaubon
Weblink https://en.wikisource.org/wiki/Marcus_Aurelius_Antoninus_-_His_Meditatio...

Context

“Carrying this theory to its extreme, the Stoic said that there could be no gradations between virtue and vice, though of course each has its special manifestations. Moreover, nothing is good but virtue, and nothing but vice is bad. Those outside things which are commonly called good or bad, such as health and sickness, wealth and poverty, pleasure and pain, are to him indifferent, αδιαφορα. All these things are merely the sphere in which virtue may act. The ideal Wise Man is sufficient unto himself in all things, autarkhs and knowing these truths, he will be happy even when stretched upon the rack. It is probable that no Stoic claimed for himself that he was this Wise Man, but that each strove after it as an ideal much as the Christian strives after a likeness to Christ.” source