The most savage controversies are those about matters as to which there is no good evidence either way.
Bertrand Russell, "An Outline of Intellectual Rubbish", Unpopular Essays (1950).
The ultimate measure of a man is not where he stands in moments of comfort and convenience, but where he stands at times of challenge and controversy.
When men differ in any matter of belief, let them meet each other manfully.
Controversy equalizes fools and wise men and the fools know it .
No great advance has ever been made in science, politics, or religion, without controversy.
Doubtless there are times when controversy becomes a necessary evil. But let us remember that it is an evil.