The Newtonian: For my part, I can easily imagine a single material point in the universe having a certain position and a certain velocity in it.
The Relativist: For my part, on the contrary, if such a material point existed, it would be absurd and impossible to speak of its position and its motion. It would have neither position nor motion nor rest. Such things can exist only with reference to other material points.
The Newtonian: That is not my opinion.
The Impartial Spectator: In order to know which of you is right we should need to try an experiment on a material point that is withdrawn from the influence of the rest of the universe. Can you try this experiment?
The Newtonian and the Relativist (together): No, unhappily.
The Metaphysician (coming up like the third thief in the fable): Then, gentlemen, I advise you to return to your telescopes, your laboratories, and your tables of logarithms. The rest is my affair.
The Newtonian and the Relativist (together): In that case we are quite sure we shall never learn anything further about it than we know or believe now.
Meantime, it is impossible to exaggerate the importance of the new light thrown on the question of Relativity by the intervention of M. Paul Painlevé at the Academy of Sciences. It will have a lasting and prodigious echo.
Will Einstein’s fine synthesis be defeated? Shall we see it sink in the controversies, doubts, and obscurities of which we have given a short account? I think not.