Epictetus. (c.A.D. 50c.A.D. 138). The Golden Sayings of Epictetus.
The Harvard Classics. 190914.
In theory it is easy to convince an ignorant person: in actual life, men not only object to offer themselves to be convinced, but hate the man who has convinced them. Whereas Socrates used to say that we should never lead a life not subjected to examination.