The followers of Darwin enter still less into the discussion of the question as to the origin of self-consciousness and of moral self-determination. Haeckel--who, in his "Natural History of Creation" and in his "Anthropogeny," expounds his whole evolution theory in all its antecedent conditions and consequences--has, indeed, much to say of the different faculties of the soul of man and animals. He traces these faculties in the case of man down to the lowest state of the most degraded races, and in the case of animals from the kermes up to the bee, from the lancelet-fish to the dog, ape, elephant and horse; and he also treats of the so-called _a priori_ knowledge which "arose only by long-enduring transmission, by inheritance of acquired adaptations of the brain, out of originally empiric or experiential knowledge _a posteriori_," (Vol. II, 345). But we look in vain in his works for a treatment of the question as to the origin of the Ego--of self-consciousness. Nowhere does he enter into the analysis of the psychological ideas; he only compares the psychical utterances of different creatures, and thinks the whole problem solved when he says: "The mental differences between the most stupid placental animals (for instance, sloths and armadillos) and the most intelligent animals of the same group (for instance dogs and apes) are, at any rate, much more considerable than the differences in the {124} intellectual life of dogs, apes, and men." Or: "If these brutish parasites are compared with the mentally active and sensitive ants, it will certainly be admitted that the psychical differences between the two are much greater than those between the highest and lowest mammals--between beaked animals, pouched animals and armadillos, on the one hand, and dogs, apes, men, on the other." The fact that in the human individual consciousness and self-consciousness are gradually developed, is to him a proof that in the organic kingdom also consciousness and self-consciousness came into existence gradually, and, indeed, hand-in-hand with the development of the nervous system; and with this result he thinks that he has relieved himself from the task of showing the "how" of the origin of self-consciousness. This becomes clearly evident from a remark about the origin of consciousness, in his "Anthropogeny," where he says that, if DuBois-Reymond had thought that consciousness is developed, he would no longer have held its origin to be a thing beyond the limits of human capacity. Haeckel likewise seems to regard the question of the origin of moral self-determination as solved or rejected, if only freedom is denied--which, indeed, is repeatedly done by him.