There must be no barriers to freedom of inquiry. There is no place for dogma in science. The scientist is free, and must be free to ask any question, to doubt any assertion, to seek for any evidence, to correct any errors.
In questions of science the authority of a thousand is not worth the humble reasoning of a single individual.
Science never tells a man how he should act; it merely shows how a man must act if he wants to attain definite ends.