Whence this material mass comes, or what its wild flight portends, we neither know nor could we, probably, comprehend even were its secret divulged to us by a superior intelligence, always conceding that there be such an intelligence, or any secret to disclose. These latter speculations lie, however, beyond the scope of my present purpose. It suffices if science permits me to postulate (a concession by science which I much doubt if it could make) that matter, as we know it, has the semblance of being what we call a substance, charged with a something which we define as energy, but which at all events simulates a vital principle resembling heat, seeking to escape into space, where it cools. Thus the stars, having blazed until their vital principle is absorbed in space, sink into relative torpor, or, as the astronomers say, die. The trees and plants diffuse their energy in the infinite, and, at length, when nothing but a shell remains, rot. Lastly, our fleshly bodies, when the union between mind and matter is dissolved, crumble into dust. When the involuntary partnership between mind and matter ceases through death, it is possible, or at least conceivable, that the impalpable soul, admitting that such a thing exists, may survive in some medium where it may be free from material shackles, but, while life endures, the flesh has wants which must be gratified, and which, therefore, take precedence of the yearnings of the soul, just as Saint Paul points out was the case with himself; and herein lies the inexorable conflict between the moral law and the law of competition which favors the strong, and from whence comes all the abominations of selfishness, of violence, of cruelty and crime. Approached thus, perhaps no historical fragment is more suggestive than the exodus of the Jews from Egypt under Moses, who was the first great optimist, nor one which is seldomer read with an eye to the contrast which it discloses between Moses the law-giver, the idealist, the religious prophet, and the visionary; and Moses the political adventurer and the keen and unscrupulous man of the world. And yet it is here at the point at which mind and matter clashed, that Moses merits most attention. For Moses and the Mosaic civilization broke down at this point, which is, indeed, the chasm which has engulfed every progressive civilization since the dawn of time. And the value of the story as an illustration of scientific history is its familiarity, for no Christian child lives who has not been brought up on it.