Following the matter into more detail, we may say that since God alone is pure energy, knowing no limitation, God alone is pure spirit. Every finite soul is joined to an organic body. "I do not admit," says Leibniz, "that there are souls entirely separate from matter, nor created spirits detached from body. . . . It is this body which the monad represents most distinctly; but since this body expresses the entire universe by the connection of all matter throughout it, the soul represents the entire universe in representing the body which belongs to it most particularly." But according to the principle of continuity there must be in the least apparent portion of matter still "a universe of creatures, of souls, of entelechies. There is nothing sterile, nothing dead in the universe. It is evident from these considerations that every living body has a dominant entelechy, which is the soul in that body, but that the members of this living body are again full of other living beings and souls," which, however, since not of so high a grade, that is, not representing the universe so fully, appear to be wholly material and subject to the "dominant" entelechy; namely, to the one which gives the law to the others by expressing more adequately the idea at which they only confusedly aim. Owing to the constant change of activity, however, these particles do not remain in constant subordination to the same entelechy (that is, do not form parts of the same body), but pass on to higher or lower degrees of "evolution," and have their places taken by others undergoing similar processes of change. Thus "all bodies are in a perpetual flux, like rivers, with parts continually leaving and entering in." Or, interpreting this figurative language, each monad is continually, in its process of development, giving law to new and less developed monads, which therefore appear as its body. The nature of matter in itself, and of its phenomenal manifestation in the body, are, however, subjects which find no explanation here, and which will demand explanation in another chapter.