"Withdraw into yourself, as far as you can. Associate with those who will make a better man of you. Welcome those whom you yourself can improve. The process is mutual; for men learn while they teach."
Lucius Annaeus Seneca
(4 B.C.-A.D. 65) Roman Stoic philosopher, statesman, dramatist, "Seneca the Younger"
Epistulae Morales ad Lucilium (Moral Letters to Lucilius), Letter VII: On crowds, line 8.