Philosophical Dictionary, by Voltaire


What is “force?” Where does it reside? Whence does it come? Does it perish? Or is it ever the same?

It has pleased us to denominate “force” that weight which one body exercises upon another. Here is a ball of two hundred pounds’ weight on this floor; it presses the floor, you say, with a force of two hundred pounds, And this you call a “dead force.” But are not these words “dead” and “force” a little contradictory? Might we not as well say “dead alive”— yes and no at once?

This ball “weighs.” Whence comes this “weight?” and is this weight a “force?” If the ball were not impeded, would it go directly to the centre of the earth? Whence has it this incomprehensible property?

It is supported by my floor; and you freely give to my floor the “vis inertiæ”—“inertiæ” signifying “inactivity,” “impotence.” Now is it not singular that “impotence” should be denominated “force?”

What is the living force which acts in your arm and your leg? What is the source of it? How can it be supposed that this force exists when you are dead? Does it go and take up its abode elsewhere, as a man goes to another house when his own is in ruins?

How can it have been said that there is always the same force in nature? There must, then, have been always the same number of men, or of active beings equivalent to men. Why does a body in motion communicate its force to another body with which it comes in contact?

These are questions which neither geometry, nor mechanics, nor metaphysics can answer. Would you arrive at the first principle of the force of bodies, and of motion, you must ascend to a still superior principle. Why is there “anything?”

Last updated Monday, December 22, 2014 at 10:55