In scientific work, those who refuse to go beyond fact rarely get as far as fact.

Science is organized common sense where many a beautiful theory was killed by an ugly fact.

Science is organized common sense where many a beautiful theory was killed by an ugly fact.

The struggle for existence holds as much in the intellectual as in the physical world. A theory is a species of thinking, and its right to exist is coextensive with its power of resisting extinction by its rivals.

I never once made a discovery ... I speak without exaggeration that I have constructed three thousand different theories in connection with the electric light ... Yet in only two cases did my experiments prove the truth of my theory.

The moment a person forms a theory, his imagination sees in every object only the traits which favor that theory