Note (return) — Chapter VI

The word "force," representing as it does a subtile menial conception, and not a phenomenon of sense, must also be banished from the domains of Positive Science as an intruder, lest its presence should lend any countenance to the idea of causation. "Forces in mechanics are only movements, produced, or tending to be produced." In order to "cancel altogether the old metaphysical notion of force," another form of expression is demanded. It is claimed that all we do know or can possibly know is the successions of phenomena in time. What, then, is the term which henceforth, in our dynamics, shall take the place of "force?" Is it "Time-succession?" Then let any one attempt to express the various forms and intensities of movement and change presented to the senses (as e.g., the phenomena of heat, electricity, galvanism, magnetism, muscular and nervous action, etc.) in terms of Time-succession, and he will at once become conscious of the utter hopelessness of physics, without the hyperphysical idea of force, to render itself intelligible. 254 What account can be rendered of planetary motion if the terms "centrifugal force" and "centripetal force" are abandoned? "From the two great conditions of every Newtonian solution, viz., projectile impulse and centripetal tendency, eject the idea of force, and what remains? The entire conception is simply made up of this, and has not the faintest existence without it. It is useless to give it notice to quit, and pretend that it is gone when you have only put a new name upon the door. We must not call it 'attraction,' lest there should seem to be a power within; we are to speak of it only as 'gravitation,' because that is only 'weight,' which is nothing but a 'fact,' as if it were not a fact that holds a power, a true dynamic affair, which no imagination can chop into incoherent successions. 255 Nor is the evasion more successful when we try the phrase, 'tendency of bodies to mutual approach.' The approach itself may be called a phenomenon; but the 'tendency' is no phenomenon, and can not be attributed by us to the bodies without regarding them as the residence of force. And what are we to say of the projectile impulse in the case of the planets? Is that also a phenomenon? Who witnessed and reported it? Is it not evident that the whole scheme of physical astronomy is a resolution of observed facts into dynamic equivalents, and that the hypothesis posits for its calculations not phenomena, but proper forces? Its logic is this: If an impulse of certain intensity were given, and if such and such mutual attractions were constantly present, then the sort of motions which we observe in the bodies of our system would follow. So, however, they also would if willed by an Omnipotent Intelligence." 256 It is thus clearly evident that human science is unable to offer any explanation of the existing order of the universe except in terms expressive of Power or Force; that, in fact, all explanations are utterly unintelligible without the idea of causation. The language of universal rational intuition is, "all phenomena are the expression of power;" the language of science is, "every law implies a force."