The sphere is the most uniform of solid bodies since every point on its surface is equidistant from its center.
Because of this, and because of its ability to revolve on an axis without straying from a fixed place, Plato (Timaeus, 33) approved the judgment of the Demiurge, who gave the world a spherical shape. Plato thought the world to be a living being and in the Laws (898) stated that the planets and stars were living as well. In this way, he enriched fantastic zoology with vast spherical animals and cast aspersions on those slow witted astronomers who failed to understand that the circular course of heavenly bodies was voluntary.
In Alexandria over five hundred years later, Origen, one of the Fathers of the Church, taught that the blessed would come back to life in the form of spheres and would enter rolling into Heaven.
During the Renaissance, the idea of Heaven as an animal reappeared in Lucilio Vanini; the Neoplatonist Marsilio Ficino spoke of the hair, teeth, and bones of the earth; and Giordano Bruno felt that the planets were great peaceful animals, warm-blooded, with regular habits, and endowed with reason. At the beginning of the seventeenth century, the German astronomer Johannes Kepler debated with the English mystic Robert Fludd which of them had first conceived the notion of the earth as a living monster, "whose whalelike breathing, changing with sleep and wakefulness, produces the ebb and flow of the sea." The anatomy, the feeding habits, the color, the memory, and the imaginative and shaping faculties of the monster were sedulously studied by Kepler.
In the nineteenth century, the German psychologist Gustav Theodor Fechner (a man praised by William James in his A Pluralistic Universe) rethought the preceding ideas with all the earnestness of a child. Anyone not belittling his hypothesis that the earth, our mother, is an organism superior to plants, animals, and men-may look into the pious pages of Fechner's Zend-Avesta. There we read, for example, that the earth's spherical shape is that of the human eye, the noblest organ of our body. Also, that "if the sky is really the home of angels, these angels are obviously the stars, for the sky has no other inhabitants."
Jorge Luis Borges, "The book of the imaginary beings", (Animals in the Form of Spheres).