VIII. But how could this give back to nature the life of which it had been robbed by advancing knowledge? Simply by making it possible for the life that had hitherto been supposed to reside in each particular thing to be transferred to the one thing of which all others were passing forms. The very process of birth, growth, and decay might now be regarded as the unceasing activity of the one ultimate reality. Aristotle and his followers expressed this by saying that the early cosmologists believed in an “eternal motion,” and in substance this is correct, though it is not probable that they said anything about the eternal motion in their writings. It is more likely that they simply took it for granted. In early times, it is not movement but rest that has to be accounted for, and we may be sure that the eternity of motion was not asserted till it had been denied. As we shall see, it was Parmenides who first denied it. The idea of a single ultimate substance, when thoroughly worked out, seemed to leave no room for motion; and after the time of Parmenides, we do find that philosophers were concerned to show how it began. At first, this would not seem to require explanation at all. Modern writers sometimes give the name of Hylozoism to this way of thinking, but the term is apt to be misleading. It suggests theories which deny the separate reality of life and spirit, whereas, in the days of Thales, and even far later, the distinction between matter and spirit had not been felt, still less formulated in such a way that it could be denied. The uncreated, indestructible reality of which these early thinkers tell us was a body, or even matter, if we choose to call it so; but it was not matter in the sense in which matter is opposed to spirit. [Sidenote: The downfall of the primitive view of the world.]