While you are experimenting, do not remain content with the surface of things. Don't become a mere recorder of facts, but try to penetrate the mystery of their origin.
Learn, compare, collect the facts!
Our success was mainly due to the fact that we stimulated the nerves of animals that easily stood on their own feet and were not subjected to any painful stimulus either during or immediately before stimulation of their nerves.
School yourself to demureness and patience. Learn to inure yourself to drudgery in science. Learn, compare, collect the facts.
Men are apt to be much more influenced by words than by the actual facts of the surrounding reality
Don't become a mere recorder of facts, but try to penetrate the mystery of their origin.
Facts are the air of the scientists. Without them you never can fly.