The fundamental principle of his philosophy was the recognition of the unchangeability of the universe as a whole, the variety of forms that we see being produced by new arrangements of its constituent parts. Such a doctrine includes, of course, the idea of the eternity of matter. Anaxagoras says, "Wrongly do the Greeks suppose that aught begins or ceases to be, for nothing comes into being or is destroyed, but all is an aggregation or secretion of pre-existent things, so that all becoming might more correctly be called becoming-mixed, and all corruption becoming-separate." In such a statement we cannot fail to remark that the Greek is fast passing into the track of the Egyptian and the Hindu. In some respects his views recall those of the chaos of Anaximander, as when he says, "Together were all things infinite in number and smallness; nothing was distinguishable. Before they were sorted, while all was together, there was no quality noticeable." To the first moving force which arranged the parts of things out of the chaos, he gave the designation of "the Intellect," rejecting Fate as an empty name, and imputing all things to Reason. He made no distinction between the Soul and Intellect. His tenets evidently include a dualism indicated by the moving force and the moved mass, an opposition between the corporeal and mental. This indicated that for philosophy there are two separate routes, the physical and intellectual. While Reason is thus the prime mover in his philosophy, he likewise employed many subordinate agents in the government of things--for instance, air, water, and fire, being evidently unable to explain the state of nature in a satisfactory way by the operation of the Intellect alone. We recognize in the details of his system ideas derived from former ones, such as the settling of the cold and dense below, and the rising of the warm and light above. In the beginning the action of Intellect was only partial; that which was primarily moved was only imperfectly sorted, and contained in itself the capability of many separations. From this point his system became a cosmogony, showing how the elements and fogs, stones, stars, and the sea, were produced. These explanations, as mighty be anticipated, have no exactness. Among his primary elements are many incongruous things, such as cold, colour, fire, gold, lead, corn, marrow, blood, &c. This doctrine implied that in compound things there was not a formation, but an arrangement. It required, therefore, many elements instead of a single one. Flesh is made of fleshy particles, bones of bony, gold of golden, lead of leaden, wood of wooden, &c. These analogous constituents are homoeomeriæ. Of an infinite number of kinds, they composed the infinite all, which is a mixture of them. From such conditions Anaxagoras proves that all the parts of an animal body pre-exist in the food, and are merely collected therefrom. As to the phenomena of life,