Full Idea
A man is as unhappy as he has convinced himself he is.
Gist of Idea
A man is as unhappy as he has convinced himself he is
Source
Seneca the Younger (Letters from a Stoic [c.60], 078)
Book Reference
Seneca: 'Letters from a Stoic (Selections)', ed/tr. Campbell,Robin [Penguin 1969], p.134
A Reaction
Seneca is a very penetrating thinker about ordinary life - an aspect of philosophy which is nowadays totally neglected by the most eminent philosophers.