Hypotheses should be subservient only in explaining the properties of things but not assumed in determining them, unless so far as they may furnish experiments.
If the experiments which I urge be defective, it cannot be difficult to show the defects; but if valid, then by proving the theory, they must render all objections invalid.
Every particle of matter is attracted by or gravitates to every other particle of matter with a force inversely proportional to the squares of their distances.
Every body persists in a state of rest or of uniform motion in a straight line, unless it is compelled to change that state by forces having impact upon it.
I keep the subject of my inquiry constantly before me, and wait till the first dawning opens gradually, by little and little, into a full and clear light.
