And yet from this vision he turns away dissatisfied: What wondrous vision! yet a vision only! Where shall I grasp thee, Nature infinite? And from this cipher of the material universe, this vision of inconceivable immensity and infinite diversity, the human spirit which is not content with the dead bones of science and has entered into communion with Nature cannot but turn away dissatisfied--and even with despair. Let me try to illustrate this in a more matter-of-fact way. The human mind discovers, let us say, that the earth is not the centre of the universe; that the sun is larger than the 'bottom of a cask,' as in the old legend Faust discovered it to be; that there are other worlds quite as large as ours; that this earth of ours is a good deal smaller than the sun and actually revolves round it; that even the sun itself is not the centre of the universe but one of many suns--one of the countless stars in that enormous starry wreath that surrounds us, and which we call the Milky Way. And we direct our telescopes to this Milky Way and find that what we took for nebula is for the most part an accumulation of countless millions of suns, each perhaps with its planets. Then, as we sweep the sky with our glass, we discover numberless little wreath-like spiral cloudlets, and find that they also are just such wreaths of countless millions of suns and solar systems, and that these seemingly tiny wreaths are revolving round some central body or system, which itself must revolve round some other, and that again round another ... until imagination fails. Is there, we ask, some final centre of all? some unmoved source of motion? Or is the material universe infinite? Then we turn our gaze in another direction and we find in the tiniest grain of sand countless millions of molecules whose atoms (or electrons), it is said, are in perpetual motion, revolving like the stars. Are then (we ask) the stars themselves nothing but molecules? Is the whole material universe nothing but some grain of sand on the shore of the ocean of eternity? We turn away dazzled, and we rest our eyes, as Socrates was wont to say, on images, on reflexions. We try to make the mystery intelligible, or at least to pacify the reason by throwing it some such sop as the theory that 'Size is only relative,' or that 'Space is only a mode of consciousness' and therefore nothing real in itself. Or we lull the mind to sleep with imaginative metaphors and speak (as Plato did) of the Central Fire of Hestia, the Hearth and Home of the Universe, or we call that mysterious unmoved centre of all motion the Throne of God. Thus we try to lay the spectre of infinite Space.