“There are those who reason well, but they are greatly outnumbered by those who reason badly.”

“I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use.”

“In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual.”

“In the sciences, the authority of thousands of opinions is not worth as much as one tiny spark of reason in an individual man.”

“To our natural and human reason, I say that these terms ‘large,’ ‘small,’ ‘immense,’ ‘minute,’ etc. are not absolute but relative; the same thing in comparison with various others may be called at one time ‘immense’ and at another ‘imperceptible.”

“The sun, with all those planets revolving around it and dependent on it, can still ripen a bunch of grapes as if it had nothing else in the universe to do.”

“Who indeed will set bounds to human ingenuity? Who will assert that everything in the universe capable of being perceived is already discovered and known?”