Zoology and botany were treated philosophically in the _Morphology_. That did not suit the professional scientists, who (as I said) crossed themselves when they saw “natural philosophy.” In the _History of Creation_ the great problems of philosophy are dealt with successively on Darwinian lines, from the zoological and botanical point of view. It was like the sinking of a deep well amongst general thoughtful readers. People felt at last what a power science had become. The old riddles of life were studied in a new light with the aid of this book. There was no predecessor in this field. Haeckel was absolutely the first to appeal to the general reader in this way. It is true that what he gave them was, strictly speaking, only an extract from his own _Morphology_, especially the second volume. But as he now arranged his matter chronologically, he converted his outline of a world-system into a “world-history”—a real “history of natural creation.” In the “Pictures of Nature” in the first volume of his _Cosmos_ Humboldt had tried to bring the natural world before his readers as a great panorama, to be taken in at one glance. But he strictly confined his study of nature to the things that actually exist; how they came to exist was not, he intimated, a subject of scientific inquiry. Haeckel proceeds to this further task. His panorama of nature does not stand out rigidly before us; it develops, under the eyes of the observer, from the formless nebula to the intelligent human being. Even on the surface this was seen to be a prodigious advance. Very plain, but very attractive, it makes its way by the force of its convincing dialectic, and places no reliance on the fireworks of rhetoric. The subtle power of it lies in the arrangement of the facts, which suddenly assume the form of a logical chain instead of being a shapeless chaos. Even if all the main ideas of the work were false, we should be compelled to regard it as one of the cleverest works that was ever written, from the dialectical point of view. But the essence of this cleverness is the way in which the grouping of the facts is made to yield the philosophic evolution, which is the thoughtful basis of the work. As the world proceeds in its natural development from the nebular cosmic raw material until it culminates in the ape and man, the reader finds himself at the same time advancing along a series of general philosophic conclusions with regard to God, the world, and man. If at the end he has retained the whole series of what are to him more or less new scientific details, he is bound to find himself caught in a strong net of philosophic conclusions.