Phil's new signature made me go hit Google for more.
http://en.wikiquote.org/wiki/Robert_A._HeinleinI read quite a bit of Heinlein's stuff when I was in high school and early college. These quotes make me want to go back and revisit his works. Here are a few examples:
"The capacity of the human mind for swallowing nonsense and spewing it forth in violent and repressive action has never yet been plumbed."
"A competent and self-confident person is incapable of jealousy in anything. Jealousy is invariably a symptom of neurotic insecurity."
"A generation which ignores history has no past  and no future."
"Courage is the complement of fear. A man who is fearless cannot be courageous. (He is also a fool.)"
"Never appeal to a man's "better nature." He may not have one. Invoking his self-interest gives you more leverage."
Truer words were never spoken.
Thanks for the reminder, Phil.