If in this book harsh words are spoken about some of the greatest among the intellectual leaders of mankind, my motive is not, I hope, the wish to belittle them. It springs rather from my conviction that, if our civilization is to survive, we must break with the habit of deference to great men. Great men may make great mistakes; and as the book tries to show, some of the greatest leaders of the past supported the perennial attack on freedom and reason. Their influence, too rarely challenged, continues to mislead those on whose defence civilization depends, and to divide them. The responsibility of this tragic and possibly fatal division becomes ours if we hesitate to be outspoken in our criticism of what admittedly is a part of our intellectual heritage. By reluctance to criticize some of it, we may help to destroy it all.

The game of science is, in principle, without end. He who decides one day that scientific statements do not call for any further test, and that they can be reg…

I see now more clearly than ever before that even our greatest troubles spring from something that is as admirable and sound as it is dangerous - from our impa…

A principle of induction would be a statement with the help of which we could put inductive inferences into a logically acceptable form. In the eyes of the uph…

Atheism ... in its philosophic aspect refuses allegiance not merely to a definite concept of God, but it refuses all servitude to the God idea, and opposes the…

'I think I'd make a better president than George Bush. I'll tell you what, George Bush and Dick Cheney have been to jail more times than I have, and I used to …

It's my honor to speak to you as the leader of your country. And the great thing about America is you don't have to listen unless you want to.