Full Idea
There is no more reliable proof of greatness than to be in a state where nothing can happen to make you disturbed.
Gist of Idea
True greatness is never allowing events to disturb you
Source
Seneca the Younger (On Anger (Book 3) [c.60], §06)
Book Reference
Seneca: 'Dialogues and Essays', ed/tr. Davie,John [Penguin 2007], p.23
A Reaction
He specifically opposes Aristotle's view that there are times when anger is appropriate, and failure to be very angry indeed is a failure of character.
Related Ideas
Idea 5235 Patient people are indignant, but only appropriately, as their reason prescribes [Aristotle]
Idea 5236 It is foolish not to be angry when it is appropriate [Aristotle]