“Conscientiously though we have sought to avoid them, the reader may find errors attributable in part to inaccurate sources and to faulty recollection. To those who may feel themselves wronged, I freely acknowledge that this is in part a book of opinion and that the opinion is my own.”

“For to err in opinion, though it be not the part of wise men, is at least human.”

“We must love them both, those whose opinions we share and those whose opinions we reject, for both have labored in the search for truth, and both have helped us in finding it.”

“The duty and the right to express one's opinion freely may be meaningless—and on occasion even injurious to the best interests of the society—if those opinions are not based on sound thought, which, in its turn, presupposes the possession of sound knowledge.”

“The world is made up for the most part of morons and natural tyrants, sure of themselves, strong in their own opinions, never doubting anything.”

“Truth gains more even by the errors of one who, with due study and preparation, thinks for himself, than by the true opinions of those who only hold them because they do not suffer themselves to think.”

“I have intentionally killed off a few people in my books, bullies who made life miserable for me in my schooldays and early teens when I couldn’t fight back. I have no plans to kill off any more – they are all dead now within my pages! However, I have a particular dislike of extremism. Everybody is entitled to their own opinion, right or wrong. When anybody tries to shove their opinion down my throat as though their beliefs are gospel, it makes me angry.”

“Though we cannot think alike, may we not love alike? May we not be of one heart, though we are not of one opinion? Without all doubt, we may. Herein all the children of God may unite, notwithstanding these smaller differences.”

“It is not the facts which guide the conduct of men, but their opinions about facts; which may be entirely wrong. We can only make them right by discussion.”

“My opinions may have changed, but not the fact that I'm right.”