"All great truths begin as blasphemies."
-George Bernard Shaw

"With most men, unbelief in one thing springs from blind belief in another."
-G. C. Lichtenberg

"The easy confidence with which I know another man's religion is folly teaches me to suspect that my own is also."
-Mark Twain

"The security provided by a long-held belief system, even when poorly founded, is a strong impediment to progress. General acceptance of a practice becomes the proof of its validity, though it lacks all other merit."
-Dr. B. Lown (invented defibrillator)

"A man receives only what he is ready to receive... The phenomenon or fact that cannot in any wise be linked with the rest of what he has observed, he does not observe."
- H. D. Thoreau

"When even the brightest mind in our world has been trained up from childhood in a superstition of any kind, it will never be possible for that mind, in its maturity, to examine sincerely, dispassionately, and conscientiously any evidence or any circumstance which shall seem to cast a doubt upon the validity of that superstition. I doubt if I could do it myself."
-Mark Twain

"There is a principle which is a bar against all information, which cannot fail to keep a man in everlasting ignorance-- that principle is contempt prior to investigation."
-Herbert Spencer

"The fact that an opinion has been widely held is no evidence whatever that it is not utterly absurd; indeed in view of the silliness of the majority of mankind, a widespread belief is more likely to be foolish than sensible."
-Bertrand Russell

"It would seem to me... an offense against nature, for us to come on the same scene endowed as we are with the curiosity, filled to overbrimming as we are with questions, and naturally talented as we are for the asking of clear questions, and then for us to do nothing about, or worse, to try to suppress the questions..."
-Lewis Thomas

"There is a cult of ignorance in the United States, and there has always been. The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means 'my ignorance is just as good as your knowledge."
-Isaac Asimov