Page:Popular Science Monthly Volume 30.djvu/821

Rh realism—realism as intense and unmitigated as that of Scotus Erigena a thousand years ago. The essence of such realism is that it maintains the objective existence of universals, or, as we call them nowadays, general propositions. It affirms, for example, that "man" is a real thing, apart from individual men, having its existence, not in the sensible but in the intelligible world, and clothing itself with the accidents of sense to make the Jack and Tom and Harry whom we know. Strange as such a notion may appear to modern scientific thought, it really pervades ordinary language. There are few people who would, at once, hesitate to admit that color, for example, exists apart from the mind which conceives the idea of color. They hold it to be something which resides in the colored object; and so far they are as much realists as if they had sat at Plato's feet. Reflection on the facts of the case must, I imagine, convince every one that "color" is—not a mere name, which was the extreme Nominalist position—but a name for that group of states of feeling which we call blue, red, yellow, and so on, and which we believe to be caused by luminiferous vibrations which have not the slightest resemblance to color; while these, again, are set afoot by states of the body to which we ascribe color, but which are equally devoid of likeness to color.

In the same way, a law of Nature, in the scientific sense, is the product of a mental operation upon the facts of Nature which come under our observation, and has no more existence outside the mind than color has. The law of gravitation is a statement of the manner in which experience shows that bodies, which are free to move, do, in fact, move toward another. But the other facts of observation, that bodies are not always moving in this fashion, and sometimes move in a contrary direction, are implied in the words "free to move." If it is a law of Nature that bodies tend to move toward one another in a certain way, it is another and no less true law of Nature that, if bodies are not free to move as they tend to do, either in consequence of an obstacle or of a contrary impulse from some other source of energy than that to which we give the name of gravitation, they either stop still or go another way.

Scientifically speaking, it is the acme of absurdity to talk of a man defying the law of gravitation when he lifts his arm. The general store of energy in the universe working through terrestrial matter is doubtless tending to bring the man's arm down; but the particular fraction of that energy which is working through certain of his nervous and muscular organs is tending to drive it up, and, more energy being expended on the arm in the upward than in the downward direction, the arm goes up accordingly. But the law of gravitation is no more defied in this case than when a grocer throws so much sugar into the empty pan of his scales that the weighted one kicks the beam.

The tenacity of the wonderful fallacy that the laws of Nature are agents instead of being, as they really are, a mere record of experience,