told that force or sentient energy is the cause of motion. If we say motion is original and eternal, we do not explain it, but assume it. If we say it is the effect of force or energy, then we are explaining it by creating a new problem. The origin of life is explained in a general way as the product of inorganic nature; the living plasm originates from inorganic carbon compounds. The physico-chemical properties of carbon are the mechanical causes of the movements of organic bodies. But what are these physical and chemical properties? If they are themselves movements, then we have simply pushed the problem back a station; if they are forces or the so-called sentient energy, then we have avoided vitalism in the organic world by previously introducing it into the inorganic world. As for the problem of the purposeful arrangement of nature, we must agree with Haeckel that the theory of evolution throws a great deal of light upon it, but we can not agree with him that it removes all difficulties and solves all riddles, as we have already pointed out.
In conclusion let us take up Haeckel's ethics and religion. The practical laws, he declares, must be in harmony with a rational Weltanschauung. Our ethical system must therefore be in harmony with the unified conception of the cosmos. The universe forms a single complete whole, the mental and moral life of man forms a part of this cosmos, hence our natural order is a unitary one. We have not two separate worlds, a physical-material world and a moral-immaterial world, but one.
The monistic cosmology has shown that there is no personal God; comparative and genetic psychology has shown that there is no immortal soul; monistic physiology has shown that there is no freedom of the will. The doctrine of evoluton shows that the eternal, necessary laws of nature which govern the inorganic world are valid also for the organic and moral world. This destroys the Kantian dualism in ethics. But there is also a positive side to ethical monism. It shows that the feeling of duty does not rest upon an illusory categorical imperative, but upon the real ground of the social instincts which we find in all higher gregarious animals. It regards as the highest aim of ethics the establishment of a healthy harmony between egoism and altruism. Man has duties towards himself and duties towards others. Both impulses, egoism and altruism, are natural laws which are equally essential to the existence of family and society. Egoism makes possible the self-preservation of the individual, altruism that of the species. The social duties are only higher developments of the social instincts. In civilized man all ethics, theoretical and practical, is connected as a normative science with his philosophy and religion. The golden rule is the fundamental law: Love your neighbor as yourself. Several christian rules of morality contradict this rule: (1) Contempt of self; exaggeration of