“At the same time, science requires the most vigorous and uncompromising skepticism, because the vast majority of ideas are simply wrong, and the only way to winnow the wheat form the chaff is by critical experiment and analysis. If you’re open to the point of gullibility and have not a microgram of skeptical sense in you, then you cannot distinguish the promising ideas from the worthless ones. Uncritically accepting every proffered notion, idea, and hypothesis is tantamount to knowing nothing. Ideas contradict one another; only through skeptical scrutiny can we decide among them. Some ideas really are better than others.”
-Carl Sagan (The Demon Haunted World)
“Ignorance more frequently begets confidence than does knowledge: it is those who know little, and not those who know much, who so positively assert that this or that problem will never be solved by science.”
-Charles Darwin (intro. to The Descent of Man)
"Ignorance is preferable to error, and he is less remote from the truth who believes nothing than he who believes what is wrong."
-Thomas Jefferson (Notes on Virginia, 1782)
"That's because I don't think it right, Socrates," he said, "For someone who's devoted so much time to the matter to be in a position to state others' beliefs, but not his own."
"But do you think it's right," I responded, "For someone to talk as if he knew what he doesn't know?"
"Of course not," he said, "Not as if he knew, but as if he'd formed opinions--he should be prepared to say what he thinks."
"But aren't ideas which aren't based on knowledge always defective in your experience?" I asked. "The best of them are blind. I mean, don't people who have a correct belief, but no knowledge, strike you as exactly like blind people who happen to be taking the right road?"
"Yes," he said.
"Well, do you want see things which are defective, blind, and deformed," I asked, "When you could be getting lucid, correct views from elsewhere?"
-Plato (506d, Republic)
"Here indeed lies the justest and most plausible objection against a considerable part of metaphysics, that they are not properly a science; but arise either from the fruitless efforts of human vanity, which would penetrate into subjects utterly unaccessible to the understanding, or from the craft of popular superstitions, which, being unable to defend themselves on fair ground, raise these intangling brambles to cover and protect their weakness. Chased from the open country, these robbers fly into the forest, and lie in wait to break in upon every unguarded avenue of the mind and overwhelm it with religious fears and prejudices."
-David Hume (48, An Enquiry Concerning Human Understanding)