Page:Popular Science Monthly Volume 78.djvu/43

Rh This argument, by which Kant reasons that all men are of one Stamm, directly implies that men and other animals are not of one Stamm, i. e., are not related through any lines of natural descent. For he makes identity of species synonymous with community of descent, and diversity of species synonymous with separateness of descent. In other words, his manner of distinguishing a species from a race rests upon wholly anti-evolutionary presuppositions.

Within the limits of a species, however, Kant holds that very considerable modifications of physical character may be brought about in the course of successive generations. Now (apart from individual variations not transmitted to offspring), there seem to Kant to be two significantly different types of heritable peculiarities: those which are invariably inherited, and those which are only alternatively inherited. Thus the. colors of a negro and a white who marry are both manifested in the offspring; children of such marriages are always mulattoes. But the complexions of the children of a dark man and a blonde woman are not necessarily a compromise between the complexions of their parents. Some or all of the children may resemble one parent only, and show (with respect to any given character) no marks of their descent from the other. By means of this distinction Kant differentiates a "race" from a "variety." Those members of a single species which also possess in common characters of the invariably hereditary sort belong to the same race; those which possess in common (and, so long as they mate with their own like, transmit to their offspring) characters that, upon cross-breeding with other types, are only alternatively hereditary, constitute only "varieties."

These definitions of "species" and "race," it is true, involve—as Kant recognizes—some revision of the classifications of the systematists.

Originally, when only similarity and dissimilarity were taken into consideration, it was customary to group classes of creatures under genera (Gattungen). But if it is their descent we are considering, it is necessary to ask whether these classes are species (Arten) or only races. The wolf, the fox, the jackal, the hyena and the domesticated dog, are so many classes of quadrupeds. If one assumes that each of them has a special descent (Abstammung), they constitute so many species; if one grants that they may have sprung from a single stock, they are simply races of that stock. In "natural history" (Naturgeschichte), which has to do only with generation and descent, the words Art and Gattung mean the same; only in "nature-description," where it is merely a question of the comparison of characters, does a distinction between