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.

There is one thing stronger than all the armies in the world; and that is an idea whose time has come.

To me there has never been a higher source of earthly honor or distinction than that connected with advances in science.

I frame no hypotheses; for whatever is not deduced from the phenomena is to be called an hypothesis; and hypotheses, whether metaphysical or physical, whether of occult qualities or mechanical, have no place in experimental philosophy.

The change in motion is proportional to the motive force impressed; and is made in the direction of the right line in which that force is impressed.

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 shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.

Plato is my friend; Aristotle is my friend, but my greatest friend is truth.

Tact is the knack of making a point without making an enemy.