"If statements of fact themselves depend upon the person who observes them, how much more distinct is the reflection of the personality of him who gives an account of methods and of philosophical specu…"

"What has been sown for the field of science will grow up for the people's welfare."

"The most all penetrating spirit before which will open the possibility of tilting not tables, but planets, is the spirit of free human inquiry. Believe only in that."

"There is nothing in science that cannot be explained to a barmaid."

"Hypotheses help and guide scientific work — the search for truth — as the tiller's plough helps the cultivation of useful plants."