The existence, among all families of mankind, of common mental and moral characteristics, as evinced in common maxims, tendencies and capacities, in the prevalence of similar traditions, and in the universal applicability of one philosophy and religion, is most easily explained upon the theory of a common origin. Among the widely prevalent traditions may be mentioned the tradition of the fashioning of the world and man, of a primeval garden, of an original innocence and happiness, of a tree of knowledge, of a serpent, of a temptation and fall, of a division of time into weeks, of a flood, of sacrifice. It is possible, if not probable, that certain myths, common to many nations, may have been handed down from a time when the families of the race had not yet separated. See Zöckler, in Jahrbuch für deutsche Theologie, 8:71-90; Max Müller, Science of Language, 2:444-455; Prichard, Nat. Hist. of Man, 2:657-714; Smyth, Unity of Human Races, 236-240; Hodge, Syst. Theol., 2:77-91; Gladstone, Juventus Mundi. 4. The argument from physiology. A. It is the common judgment of comparative physiologists that man constitutes but a single species. The differences which exist between the various families of mankind are to be regarded as varieties of this species. In proof of these statements we urge: (_a_) The numberless intermediate gradations which connect the so-called races with each other. (_b_) The essential identity of all races in cranial, osteological, and dental characteristics. (_c_) The fertility of unions between individuals of the most diverse types, and the continuous fertility of the offspring of such unions. Huxley, Critiques and Addresses, 163—“It may be safely affirmed that, even if the differences between men are specific, they are so small that the assumption of more than one primitive stock for all is altogether superfluous. We may admit that Negroes and Australians are distinct species, yet be the strictest monogenists, and even believe in Adam and Eve as the primeval parents of mankind, _i. e._, on Darwin’s hypothesis”; Origin of Species, 118—“I am one of those who believe that at present there is no evidence whatever for saying that mankind sprang originally from more than a single pair; I must say that I cannot see any good ground whatever, or any tenable evidence, for believing that there is more than one species of man.” Owen, quoted by Burgess, Ant. and Unity of Race, 185—“Man forms but one species, and differences are but indications of varieties. These variations merge into each other by easy gradations.” Alex. von Humboldt: “The different races of men are forms of one sole species,—they are not different species of a genus.”