I have told man’s story up to a point about half-way from his origin to his annihilation. Behind lies the vast span which includes the whole Terrestrial and Venerian ages, with all their slow fluctuations of darkness and enlightenment. Ahead lies the Neptunian age, equally long, equally tragic perhaps, but more diverse, and in its last phase incomparably more brilliant. It would not be profitable to recount the history of man on Neptune on the scale of the preceding chronicle. Very much of it would be incomprehensible to terrestrials, and much of it repeats again and again, in the many Neptunian modes, themes that we have already observed in the Terrestrial or the Venerian movements of the human symphony. To appreciate fully the range and subtlety of the great living epic, we ought, no doubt, to dwell on its every movement with the same faithful care. But this is impossible to any human mind. We can but attend to significant phrases, here and there, and hope to capture some fragmentary hint of its vast intricate form. And for the readers of this book, who are themselves tremors in the opening bars of the music, it is best that I should dwell chiefly on things near to them, even at the cost of ignoring much that is in fact greater.

Before continuing our long flight let us look around us. Hitherto we have passed over time’s fields at a fairly low altitude, making many detailed observations. Now we shall travel at a greater height and with speed of a new order. We must therefore orientate ourselves within the wider horizon that opens around us; we must consider things from the astronomical rather than the human point of view. I said that we were half-way from man’s beginning to his end. Looking back to that remote beginning we see that the span of time which includes the whole career of the First Men from Pithecanthropus to the Patagonian disaster is an unanalysable point. Even the preceding and much longer period between the first mammal and the first man, some twenty-five millions of terrestrial years, seems now inconsiderable. The whole of it, together with the age of the First Men, may be said to lie half-way between the formation of the planets, two thousand million years earlier, and their final destruction, two thousand million years later. Taking a still wider view, we see that this aeon of four thousand million years is itself no more than a moment in comparison with the sun’s age. And before the birth of the suns the stuff of this galaxy had already endured for aeons as a nebula. Yet even these aeons look brief in relation to the passage of time before the myriad great nebulae themselves, the future galaxies, condensed out of the all-pervading mist in the beginning. Thus the whole duration of humanity, with its many sequent species and its incessant downpour of generations, is but a flash in the lifetime of the cosmos.

Spatially, also, man is inconceivably minute. If in imagination we reduce this galaxy of ours to the size of an ancient terrestrial principality, we must suppose it adrift in the void with millions of other such principalities, very remote from one another. On the same scale the all-embracing cosmos would bulk as a sphere whose diameter was some twenty times greater than that of the lunar orbit in your day; and somewhere within the little wandering asteroid-like principality which is our own universe, the solar system would be an ultra-microscopic point, the greatest planet incomparably smaller.

We have watched the fortunes of eight successive human species for a thousand million years, the first half of that flicker which is the duration of man. Ten more species now succeed one another, or are contemporary, on the plains of Neptune. We, the Last Men, are the Eighteenth Men. Of the eight pre-Neptunian species, some, as we have seen, remained always primitive; many achieved at least a confused and fleeting civilization, and one, the brilliant Fifth, was already wakening into true humanity when misfortune crushed it. The ten Neptunian species show an even greater diversity. They range from the instinctive animal to modes of consciousness never before attained. The definitely subhuman degenerate types are confined mostly to the first six hundred million years of man’s sojourn on Neptune. During the earlier half of this long phase of preparation, man, at first almost crushed out of existence by a hostile environment, gradually peopled the huge north; but with beasts, not men. For man, as man, no longer existed. During the latter half of the preparatory six hundred million years, the human spirit gradually awoke again, to undergo the fluctuating advance and decline characteristic of the pre-Neptunian ages. But subsequently, in the last four hundred million years of his career on Neptune, man has made an almost steady progress toward full spiritual maturity.

Let us now look rather more closely at these three great epochs of man’s history.