"It is not what the man of science believes that distinguishes him, but how and why he believes it. His beliefs are tentative, not dogmatic; they are based on evidence, not on authority or intuition."
"It is evident as a matter of logic that, since they (world religions) disagree, not more than one of them can be true."
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts."
"We know very little, and yet it is astonishing that we know so much, and still more astonishing that so little knowledge can give us so much power."
"There are two motives for reading a book; one, that you enjoy it; the other, that you can boast about it."
"What is wanted is not the will to believe, but the will to find out, which is the exact opposite."