"The frame of nature, and the system of the world, we are to observe by the phenomena, and not to frame by imagination."

"My powers are ordinary. Only my application brings me success."

"Gravity must be caused by some agent acting constantly according to certain laws; but whether this agent be material or immaterial, I have left to the consideration of my readers."

"I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier sh…"

"It is the weight, not numbers of experiments that is to be regarded."