“In like manner, if I let myself believe anything on insufficient evidence, there may be no great harm done by the mere belief; it may be true after all, or I may never have occasion to exhibit it in outward acts. But I cannot help doing this great wrong towards Man, that I make myself credulous. The danger to society is not merely that it should believe wrong things, though that is great enough; but that it should become credulous, and lose the habit of testing things and inquiring into them; for then it must sink back into savagery.”

“It is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence.”

“We may believe what goes beyond our experience, only when it is inferred from that experience by the assumption that what we do not know is like what we know.”

“I have a great mind to believe in Christianity for the mere pleasure of fancying I may be damned.”

“Man often becomes what he believes himself to be. If I keep on saying to myself that I cannot do a certain thing, it is possible that I may end by really becoming incapable of doing it. On the contrary, if I have the belief that I can do it, I shall surely acquire the capacity to do it even if I may not have it at the beginning.”

“I try to make myself realize that I have learned the difference between right and wrong. That there is such a thing as right and wrong. But instead I've learned that these are things - this "right", this "wrong"- these are things that we are told. Simply told to believe. These are things we have not tested. And while most of the things we are told may be true, it is not until we have tested them, taunted them, flaunted them, that we truly know they are right. Or wrong. Or true. Or false. Or somewhere in-the-fucking-between. And I think I know now a little better which is which. And I also know I'll never quit testing this world. I'll never rely on common knowledge. Or common denominators. Or even common sense, for that matter.”

“We must know the truth; and we must avoid error,--these are our first and great commandments as would-be knowers; but they are not two ways of stating an identical commandment, they are two separable laws. Although it may indeed happen that when we believe the truth A, we escape as an incidental consequence from believing the falsehood B, it hardly ever happens that by merely disbelieving B we necessarily believe A. We may in escaping B fall into believing other falsehoods, C or D, just as bad as B; or we may escape B by not believing anything at all, not even A.”