still more—which he recognized as due to the progress of his own mind.
The article "Progress, its Law and Cause," projected, as we have seen, in 1854, was written early in 1857. In the first half of it the transformation of the homogeneous into the heterogeneous is traced throughout all orders of phenomena; in the second half the principle of transformation is deduced from the law of the multiplication of effects. In this essay, moreover, there is indicated the application of the general law of Evolution to the production of species. It is shown that there "would not be a substitution of a thousand more or less modified species for the thousand original species; but, in place of the thousand modified species, there would arise several thousand species, or varieties, or changed forms;" and that "each original race of organisms would become the root from which diverged several races differing more or less from it and from each other." It is further argued that the new relations in which animals would be placed toward one another would initiate further differences of habit and consequent modifications, and that "there must arise, not simply a tendency toward the differentiations of each race of organisms into several races, but also a tendency to the occasional production of a somewhat higher organism." The case of the divergent varieties of man, some of them higher than others, caused in this same manner, is given in illustration. Throughout the argument there is a tacit implication that, as a consequence of the cause of Evolution, the production of species will go on, not in ascending linear series, but by perpetual divergence and redivergence—branching and again branching. The general conception, however, differs from that of Mr. Darwin in this—that adaptation and readaptation to continually-changing conditions is the only process recognized there is no recognition of "spontaneous variations," and the natural selection of those that are favorable.
During the summer of 1857 Mr. Spencer wrote the "Origin and Function of Music," published in Fraser's Magazine for October. Like nearly all of his other writings, this interesting article is dominated by the idea of Evolution. The general law of nervo-motor action in all animals is shown to furnish an explanation of the tones and cadences of emotional speech; and it is pointed out that from these music is evolved by simple exaltation of all the distinctive traits, and carrying them out into ideal combination. A further step was taken, the same year, in the development of the doctrine of Evolution, which is indicated in the article entitled "Transcendental Physiology." It was there explained that the multiplication of effects was not the only cause of the universal change from homogeneity to heterogeneity, but that there was an antecedent principle to be recognized, viz., the Instability of the Homogeneous. The physiological illustrations of the law are mainly dwelt upon, though its other applications are indicated.