tliat it is very hard for us to perceive the strangeness, yes, the absurdity of it. When we reflect that all we know of any particular substance is of its properties, we see that the thought that it is still present, but has no longer any of its properties, is not far removed from pure nonsense. In fact, this purely formal conception only serves to help us harmonize the general facts of chemical processes, particularly the stoichiometrical laws of mass, with the arbitrary conception of a matter unchangeable in itself.
But even with this extended conception of matter and the necessary corollaries besides, we can not comprehend the mass of phenomena—not once in inorganic Nature. Matter is thought of as something at rest, unchangeable; in order to reconcile this thought with the view of the constantly changing world, we have to complement it with another, independent of it, which shall bring changeableness to pass. Such a supplementary idea was set forth by Galileo, the creator of scientific physics, in the conception of force, as the constant cause of motion. Galileo had discovered a highly important invariant for the variable phenomena of free and induced falling. By the application of a self-existing gravity, the effects of which continuously accumulate, he made the complete explanation of these processes possible. The pregnancy of this conception was demonstrated by Newton, who, with his thought that the same force was operative as a function of the distance between the heavenly bodies, conquered the whole visible stellar world for science. This advance it was, chiefly, which aroused the conviction that all other physical phenomena could be accounted for in the same way as those of astronomy by the same auxiliary. Then when it resulted, further, at the beginning of our century, through the labors of a number of eminent astronomers, principally French, not only that Newton's law of gravitation could account for the motions of the heavenly bodies in their larger features, but that it sustained the closer and far more thorough second test of accounting for the deviations from the typical forms of motion, the perturbations, the confidence in the fruitfulness of this conception was increased in an extraordinary measure. What could be more readily suggested than the supposition that the theory which had been competent to account so completely for the motions of the great world was also the right and only means of reducing the processes in the smaller world of atoms to scientific control? Thus arose the mechanical view of Nature, according to which all phenomena, especially in inanimate Nature, were traced back ultimately to the motions of atoms under the same laws as were recognized for the heavenly bodies. It was a necessary consequence that this conception of the realm of inorganic Nature should be applied to animate Nature
