A Guide to the Good Life: The Ancient Art of Stoic Joy

by William B. Irvine

Stoic tranquility was a psychological state marked by the absence of negative emotions, such as grief, anger, and anxiety, and the presence of positive emotions, such as joy.

Thus, for the Roman Stoics, the pursuit of virtue and the pursuit of tranquility are components of a virtuous circle—indeed, a doubly virtuous circle: The pursuit of virtue results in a degree of tranquility, which in turn makes it easier for us to pursue virtue.

The psychologists Shane Frederick and George Loewenstein have studied this phenomenon and given it a name: hedonic adaptation.

What Stoics discover, though, is that willpower is like muscle power: The more they exercise their muscles, the stronger they get, and the more they exercise their will, the stronger it gets. Indeed, by practicing Stoic self-denial techniques over a long period, Stoics can transform themselves into individuals remarkable for their courage and self-control.

What matters most, says Epictetus, is not our ability to spout Stoic principles but our ability to live in accordance with them.

Punishment, in other words, should be “an expression not of anger but of caution.”

Seneca