generalises this abstraction till at last it reaches a perfectly generalised absurdity and thing without any meaning--the law of gravitation.[23] The statement that "every particle in the universe attracts every other particle with a force proportional to the mass of the attracting particle and inversely proportional to the square of the distance between the two" is devoid of meaning--the human mind can give no definite meanings to the words "mass," "attract," and "force," which do not overlap and stultify each other. The law in every way baffles intelligence. Newton, who invented it, declared that no philosophic mind would suppose that bodies could thus act on one another "without the mediation of anything else by and through which their action might be conveyed;" scientific men to-day are fain to see that a material mediation of this kind would only make the law still more remote from our comprehension than it already is, while, on the other hand, an immaterial mediation or a fourth-dimensional mediation, such as some propose, would simply remove the problem out of the regions of scientific analysis.[24] Again, the form of the law is declared to be the inverse square of the distance; but this is the law by the nature of space itself of any perfect radiation, and if true of gravitation involves the conclusion that that radiation of force (whatever its nature may be) takes place without loss or dissipation of any kind. This would make gravitation absolutely unique among phenomena. More than this, its propagation is supposed to be _instantaneous_ over the most enormous distances of space, and to take place always unhindered and unretarded, whatever be the number or the nature of the bodies between! What can be more clear than that the law is simply metaphysical--a projection into a monstrous universality and abstraction, of partially understood phenomena in a particular region of observation--a Brocken-shadow on the background of Nature of the observer's own momentary attitude of thought?