"In principio it is impossible to prove from experiments that something is non-existent."

"Fermat applied his method of tangents to many difficult problems. The method has the form of the now-standard method of differential calculus, though it begs entirely the difficult theory of limits."

"The game of science is, in principle, without end. He who decides one day that scientific statements do not call for any further test, and that they can be regarded as finally verified, retires from t…"

"A view of the constitution of matter which recommended itself to Faraday as preferable to the one ordinarily held appears to me to be exactly the view I endeavor to picture as the constitution of spir…"

"You see, I understand Mr. Khan, that your son and your family are Muslim and Muslims do indeed serve in our armed forces. But in the military I know, we do not celebrate that which divides, but rather…"