Haeckel is married, with a big brood of children and grandchildren about him. Some of his own children and the grandchildren are about the same age, for Haeckel has two broods, having had two wives, both of whom sympathized with the Teddine philosophy. With the whole household, including servants, the great scientist is on terms of absolute good camaraderie. The youngsters ride on his back; the older girls decorate him with garlands; the boys work with him in the garden, or together they tramp the fields and climb the hills. But when it comes to study he goes to his own room in the Zoology Building, enters in and locks the door. When he travels he travels alone, without companion or secretary. Travel to him means intense work; and intense work means to him intense pleasure. Solitude seems necessary to close, consecutive thinking; and in the solitude of travel, through jungle, forest, crowded city, or across wide oceans, Haeckel finds his true and best self. Then it is that he puts his soul in touch with the Universal and realizes most fully Goethe's oft-repeated dictum, "All is one." And, indeed, to Goethe must be given the credit of preparing the mind of Haeckel for Darwinism. In his book, "The Freedom and Science of Teaching," Haeckel applies the poetic monistic ideas of Goethe to biology and then to sociology. "All is one." And this oneness that everywhere exists is simply a differentiation of the original single cell. The evolution of the cell mirrors the evolution of the species: the evolution of the individual mirrors the evolution of the race. This law, expressed by Goethe, is the controlling shibboleth in all Haeckel's philosophy. In embryology he has proved it to the satisfaction of the scientific world. When he applies it to sociology our Bellamys are looking backward to Sir Thomas More, and expect a sudden transformation to a Utopia, not unlike the change which the good old preachers used to tell us we would experience "in the twinkling of an eye." Haeckel builds on Darwin and shows that as the Cirripedia which makes the bottom of the ocean, the coral "insect" which rears dangerous reefs and even mountain-ranges, and Rhizopods that make the chalk cliffs possible, did not change the earth's crust in the twinkling of an eye, so neither can the efforts of man instantly change the social condition. Souls do not make lightning changes. Karl Marx thought society would change in the twinkling of a ballot, but he was not a Monist, and therefore did not realize that humanity is a solidarity of souls, evolved from very lowly forms and still slowly ascending.