To disagree, one doesn’t have to be disagreeable. Barry Goldwater
Just as war is freedom’s cost, disagreement is freedom’s privilege. Bill Clinton
Honest disagreement is often a good sign of progress. Mahatma Gandhi
The beginning of thought is in disagreement – not only with others but also with ourselves. Eric Hoffer
The people to fear are not those who disagree with you, but those who disagree with you and are too cowardly to let you know. Napoleon Bonaparte
When I disagree with a rational man, I let reality be our final arbiter; if I am right, he will learn; if I am wrong, I will; one of us will win, but both will profit. Ayn Rand