But men live on illusions and give way but reluctantly to the progress of science, in order to devote themselves arduously to the ideal of the new truths which rise out of the essence of things of which mankind is a part. After the geocentric illusion had been destroyed, the anthropocentric illusion still remained. On earth, man was still supposed to be king of creation, the center of terrestrial life. All Species of animals, plants and minerals were supposed to be created expressly for him, and to have had from time immemorial the forms which we see now, so that the fauna and flora living on our planet have always been what they are today. And Cicero, for instance, said that the heavens were placed around the earth and man in order that he might admire the beauty of the starry firmament at night, and that animals and plants were created for his use and pleasure. But in 1856 Charles Darwin came and, summarizing the results of studies that had been carried on for a century, destroyed in the name of science the superb illusion that man is the king and center of creation. He demonstrated, amid the attacks and calumnies of the lovers of darkness, that man is not the king of creation, but merely the last link of the zoological chain, that nature is endowed with eternal energies by which animal and plant life, the same as mineral life (for even in crystals the laws of life are at work), are transformed from the invisible microbe to the highest form, man. The anthropocentric illusion rebelled against the word of Darwin, accusing him of lowering the human life to the level of the dirt or of the brute. But a disciple of Darwin gave the right answer, while propagating the Darwinian theory at the university of Jena. It was Haeckel, who concluded: "For my part, and so far as my human consciousness is concerned, I prefer to be an immensely perfected ape rather than to be a degenerated and debased Adam."