Ernst Haeckel is an eminent comparative anatomist and physiologist, who has earned a wide and deserved reputation by his able and laborious studies of the calcareous sponges, the radiolarians, and other low forms of life. In his work on _The Evolution of Man_ he applies this knowledge to the solution of the problem of the origin of humanity, and sets himself not only to illustrate, but to "prove," the descent of our species from the simplest animal types, and even to overwhelm with scorn every other explanation of the appearance of man except that of spontaneous evolution. He is not merely an evolutionist, but what he terms a "monist," and the monistic philosophy, as defined by him, includes certain negations and certain positive principles of a most comprehensive and important character. It implies the denial of all spiritual or immaterial existence. Man is to the monist merely a physiological machine, and nature is only a greater self-existing and spontaneously-moving aggregate of forces. Monism can thus altogether dispense with a Creative Will as originating nature, and adopts the other alternative of self-existence or causelessness for the universe and all its phenomena. Again, the monistic doctrine necessarily implies that man, the animal, the plant, and the mineral are only successive stages of the evolution of the same primordial matter, constituting thus a connected chain of being, all the parts of which sprang spontaneously from each other. Lastly, as the admixture of primitive matter and force would itself be a sort of dualism, Haeckel regards these as ultimately one, and apparently resolves the origin of the universe into the operation of a self-existing energy having in itself the potency of all things. After all, this may be said to be an approximation to the idea of a Creator, but not a living and willing Creator. Monism is thus not identical with pantheism, but is rather a sort of atheistic monotheism, if such a thing is imaginable; and vindicates the assertion attributed to a late lamented physical philosopher--that he had found no atheistic philosophy which had not a God somewhere.