"A presumptuous scepticism that rejects facts without examination of their truth, is, in some respects, more injurious than unquestioning credulity."—Humboldt.

"One good experiment is of more value than the ingenuity of a brain like Newton's. Facts are more useful when they contradict, than when they support, received theories."—Sir Humphry Davy.

"The perfect observer in any department of science will have his eyes, as it were, opened, that they may be struck at once by any occurrence which, according to received theories, ought not to happen, for these are the facts which serve as clues to new discoveries."— Sir John Herschell.

"Before experience itself can be used with advantage, there is one preliminary step to make which depends wholly on ourselves: it is, the absolute dismissal and clearing the mind of all prejudice, and the determination to stand or fall by the result of a direct appeal to facts in the first instance, and of strict logical deduction from them afterwards."—Sir John Herschell.

"With regard to the miracle question, I can only say that the word 'impossible' is not, to my mind, applicable to matters of philosophy. That the possibilities of nature are infinite is an aphorism with which I am wont to worry my friends."—Professor Huxley.