One must therefore take refuge in philosophy; this pursuit, not only in the eyes of good men, but also in the eyes of those who are even moderately bad, is a sort of protecting emblem.For speechmaking at the bar, or any other pursuit that claims the people’s attention, wins enemies for a man; but philosophy is peaceful and minds her own business. Men cannot scorn her; she is honoured by every profession, even the vilest among them. Evil can never grow so strong, and nobility of character can never be so plotted against, that the name of philosophy shall cease to be worshipful and sacred.
Seneca, Letters from a Stoic
Minds and Brains 