"Hypotheses non fingo. (I frame no hypotheses.)"

"Every body continues in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impressed upon it."

"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."

"Gravity explains the motions of the planets, but it cannot explain who sets the planets in motion."