A few selections:
"The study of history is a powerful antidote to contemporary arrogance. It is humbling to discover how many of our glib assumptions, which seem to us novel and plausible, have been tested before, not once but many times and in innumerable guises; and discovered to be, at great human cost, wholly false."
"...you can never be happy and dress yourself solely in the glass of other men's approval."
-Nicholas Flood Davis5
"You know, doing what is right is easy. The problem is knowing what is right."
-Lyndon B. Johnson8