What he and his school seem to have felt was that there was a danger in all this talk of water or air or other material symbol, or even of the _indefinite_ or _characterless_ as the original of all,--the danger, namely, that one should lose sight of the idea of law, of rationality, of eternal self-centred force, and so be carried away by some vision of a gradual process of evolution from mere emptiness to fulness of being. Such a position would be not dissimilar to that of many would-be metaphysicians among evolutionists, who, not content with the doctrine of evolution as a theory in science, an ordered and organising view of observed facts, will try to elevate it into a vision of what is, and alone is, behind the observed facts. They fail to see that the more blind, the more accidental, so to speak, the process of differentiation may be; the more it is shown that the struggle for existence drives the wheels of progress along the {37} lines of least resistance by the most commonplace of mechanical necessities, in the same proportion must a law be posited behind all this process, a reason in nature which gathers up the beginning and the ending. The protoplasmic cell which the imagination of evolutionists places at the beginning of time as the starting-point of this mighty process is not merely this or that, has not merely this or that quality or possibility, it _is_; and in the power of that little word is enclosed a whole world of thought, which is there at the first, remains there all through the evolutions of the protoplasm, will be there when these are done, is in fact independent of time and space, has nothing to do with such distinctions, expresses rather their ultimate unreality. So far then as Parmenides and his school kept a firm grip on this other-world aspect of nature as implied even in the simple word _is_, or _be_, so far they did good service in the process of the world's thought. On the other hand, he and they were naturally enough disinclined, as we all are disinclined, to remain in the merely or mainly negative or defensive. He would not lose his grip of heaven and eternity, but he would fain know the secrets of earth and time as well. And hence was fashioned the second part of his poem, in which he expounds his theory of the world of opinion, or guess-work, or observation. [99]