Page:Popular Science Monthly Volume 15.djvu/845

Rh by invalid reasoning, and that the sanction of a name so eminent among American physiologists should be given to views which do not accord with the results of the best and most recent investigations on this subject.



HE old scholastic controversy as to the reality of universals has its analogue in modern times. Formerly the strife had its religious implications, and it was from the arsenal of theology that the defenders of realism procured their weapons. Theological realism has now been virtually abandoned, and it is to metaphysics that the realists appeal to defend their abstractions from the searching analysis to which scientific modes of thought would most assuredly subject them.

Realism was the doctrine that universals have a real existence, entirely independent of the concretes from which they were generalized. It was held, for instance, by the older realists, that there is in the universe a perfect circle, freed from the imperfections of those we are able to construct; that this is not an idea generalized from the circles we see; that it is not the result of abstracting the imperfections that are inseparable from any circle we can draw and confining our attention alone to its perfections; but that there really exists an archetype of which circles as we know them are merely imperfect reproductions. This doctrine, even among the scholastics, found its strong opponents, and in its cruder forms was obliged to succumb. In metaphysics, however, realism, in a more refined form, found a soil fitted to its luxuriant growth, and the belief in entities and quiddities, and the other metaphysical essences associated with these, spread to such an extent that the successive influences of men as powerful as Locke and Hume sufficed to check rather than to exterminate it. The scientific tendency of thought, in which these men were pioneers, is now making havoc among the heirlooms of a past civilization. This tendency, which accepts nothing on mere assertion, and which forces every belief to produce its credentials, is now bringing its methods to bear upon the entities of metaphysics, and proving conclusively that they are of no nobler descent than the phenomena in which they originated.

The decadence of realism affords so striking an example of the general change in the conception of nature that has taken place within the past three centuries as, to a certain extent, to justify Comte's generalization as to the natural development of thought. There could, historically, hardly be a better example of this change than in the 