Seen on lewrockwell.com:

"Battle doesn’t determine who is right. Only who is left." -- Peter Bowman, from 'Beach Red'

and Somer came across this one:

"Good intentions will always be pleaded for every assumption of authority. It is hardly too strong to say that the Constitution was made to guard the people against the dangers of good intentions. There are men in all ages who mean to govern well, but they mean to govern. They promise to be good masters, but they mean to be masters." -- Daniel Webster