Page:Mind (Old Series) Volume 9.djvu/264

252 THOMAS WHITTAKER : carried round by spheres. And with the system of the planetary and other spheres the concentric arrangement of the four elements disappears also. In opposition to the Aristotelian doctrine, Bruno argues that the elements have no fixed order of position with respect to one another. They are, besides, never found in nature pure or unmixed. All substances in nature are mixed, and their composition is perpetually changing. There is no fifth element or " quintessence " in Bruno's system. The stars and planets are not simple bodies, but are of mixed composition like the earth. All the bodies in the universe are made of the same elements or proximate principles as well as of the same primordial matter. In the sun and the stars fire predominates ; in the earth and the planets (in which class the comets are included) water pre- dominates. Bodies of the first class shine with their own light, bodies of the second class with a reflected light. But the element of fire is not absent from the earth. And water, being, as Thales taught, 1 the basis of all substances, the common element that binds together the parts of the ele- ments of earth and water, cannot be absent from the sun. Heat and light, besides, are not sensible in themselves. Light, for example, is itself invisible ; it is visible only by means of the body in which it inheres. What we call flame or fire is light or heat inherent in a moist body. Hence the sun is not without opacity and coldness as the earth is not without heat and light. The name of " ether " is given by Bruno not to the " quintessence " of which the stars were supposed to be made, but to space as distinguished from matter. He identifies the " immense ethereal space " of his cosmology with the " vacuum " of the Epicureans. Of this vacuum he says " God is the fulness ". The " ether," or " heaven," or " space," as distinguished from the bodies it contains, is ingenerable, incorruptible and immovable. Being infinite it has properly no figure ; but we may des- cribe it, with Xenophanes, by the similitude of a sphere the centre of which is everywhere and the circumference no- where. Since every point of space may in turn be regarded as the centre, all motions may be said to be up or down, towards 1 Bruno ascribes this doctrine not only to Thales, but also to " Moses and the Babylonians ". Water, being an element in which coldness and darkness predominate, is, he argues, the representative of matter in the Mosaic and Babylonian cosmogonies ; light or fire, of spirit. He himself often makes the sun the symbol of spirit or form or the active principle in nature ; the earth, of matter or the passive principle.