The Ten books on Architecture, Vitruvius
Book VI Introduction

"The man of learning is the only person in the world who is neither a stranger when in a foreign land, nor friendless when he has lost his intimates and relatives; on the contrary, he is a citizen of every country, and can fearlessly look down upon the troublesome accidents of fortune. But he who thinks himself entrenched in defences not of learning but of luck, moves in slippery paths, struggling through life unsteadily and insecurely."
Theophrastus