Reader. Do you discriminate between “force” and “quantity of action”?
Büchner. No, sir.
Reader. Do you identify “force” with “quantity of movement”?
Büchner. Yes, sir.
Reader. Then it is evident that you confound force, power, quantity of action, and quantity of movement.
Büchner. All these terms are substantially identical in science.
Reader. True, the lowest school of physicists considers them as substantially identical, and in this manner they succeed in persuading themselves and many others that the quantity of living force existing in the world is always invariably the same. But, after all, those physicists speak very incorrectly, and are not to be followed in their blundering terminology. A quantity of movement is not an action, but the result of action; and a quantity of action is not a power, but the exertion of power. In fact, the same power acts with different intensity in different conditions; and equal actions produce different movements in bodies actually subject to different dynamical determinations. Hence it is impossible to admit that powers, actions, and movements are synonymous.
And now, which of these three notions do you choose to identify with force? If you say that force is “a quantity of movement,” then it will be false that no force is ever lost; for any quantity of movement can be lost without compensation. Thus a stone thrown up vertically loses its quantity of movement without compensation.[153] If you say that force is “a quantity of action,” it will again be false that no force is ever lost; for all successive actions successively pass away, and continually change their direction and their intensity, according as the distances and positions of the bodies acted on are altered. Lastly, if you say that force is “power,” then it is false that forces are transformed or convertible; for the power of each element of matter remains unalterably the same, as you yourself acknowledge, throughout all the vicissitudes of time. “A particle of iron,” you say with Dubois-Reymond, “is and remains the same, whether it crosses the horizon in the meteoric stone, rushes along in the wheel of the steam-engine, or circulates in the blood through the temples of the poet.”
Büchner. Would you, then, repudiate science?
Reader. By no means. I love and respect true science. I only repudiate that false and presumptuous dogmatism which prompts a class of physicists to draw general conclusions from particular, and often questionable, premises.