“Sit down before fact as a little child, be prepared to give up every preconceived notion, follow humbly wherever and to whatever abysses nature leads, or you shall learn nothing. I have only begun ...”

“What we call rational grounds for our beliefs are often extremely irrational attempts to justify our instincts.”

“With theology as a code of dogmas which are to be believed, or at any rate repeated, under penalty of present or future punishment, or as a storehouse of anaesthetics for those who find the pains o...”

“Wherever sufficiently numerous series of the remains of any given group, which has endured for a long space of time, are carefully examined, their morphological relations are never in discordance w...”

“I am too much of a skeptic to deny the possibility of anything.”

“From the dawn of exact knowledge to the present day, observation, experiment, and speculation have gone hand in hand; and, whenever science has halted or strayed from the right path, it has been, e...”

“Should we not be concerned as to whether this fear of error is not just the error itself?”

“An error does not become truth by reason of multiplied propagation, nor does the truth become error because nobody will see it. 1924-1926)”

“Error, indeed is never set forth in its naked deformity, lest, being thus exposed, it should at once be detected. But it is craftily decked out in an attractive dress, so as, by its outward form, t...”

“I sensed that if I were ever to meet [Senator Orrin] Hatch face-to-face there would be little that we could agree upon. There was something about watching Hatch that reminded me of unpleasant, futi...”

“Reality is, you know, the tip of an iceberg of irrationality that we've managed to drag ourselves up onto for a few panting moments before we slip back into the sea of the unreal.”

“To be against rationalization is not the same as to be opposed to reasoning.”