This book has two authors, one contemporary with its readers, the other an inhabitant of an age which they would call the distant future. The brain that conceives and writes these sentences lives in the time of Einstein. Yet I, the true inspirer of this book, I who have begotten it upon that brain, I who influence that primitive being’s conception, inhabit an age which, for Einstein, lies in the very remote future.

The actual writer thinks he is merely contriving a work of fiction. Though he seeks to tell a plausible story, he neither believes it himself, nor expects others to believe it. Yet the story is true. A being whom you would call a future man has seized the docile but scarcely adequate brain of your contemporary, and is trying to direct its familiar processes for an alien purpose. Thus a future epoch makes contact with your age. Listen patiently; for we who are the Last Men earnestly desire to communicate with you, who are members of the First Human Species. We can help you, and we need your help.

You cannot believe it. Your acquaintance with time is very imperfect, and so your understanding of it is defeated. But no matter. Do not perplex yourselves about this truth, so difficult to you, so familiar to us of a later aeon. Do but entertain, merely as a fiction, the idea that the thought and will of individuals future to you may intrude, rarely and with difficulty, into the mental processes of some of your contemporaries. Pretend that you believe this, and that the following chronicle is an authentic message from the Last Men. Imagine the consequences of such a belief. Otherwise I cannot give life to the great history which it is my task to tell.

When your writers romance of the future, they too easily imagine a progress toward some kind of Utopia, in which beings like themselves live in unmitigated bliss among circumstances perfectly suited to a fixed human nature. I shall not describe any such paradise. Instead, I shall record huge fluctuations of joy and woe, the results of changes not only in man’s environment but in his fluid nature. And I must tell how, in my own age, having at last achieved spiritual maturity and the philosophic mind, man is forced by an unexpected crisis to embark on an enterprise both repugnant and desperate.

I invite you, then, to travel in imagination through the aeons that lie between your age and mine. I ask you to watch such a history of change, grief, hope, and unforeseen catastrophe, as has nowhere else occurred, within the girdle of the Milky Way. But first, it is well to contemplate for a few moments the mere magnitudes of cosmical events. For, compressed as it must necessarily be, the narrative that I have to tell may seem to present a sequence of adventures and disasters crowded together, with no intervening peace. But in fact man’s career has been less like a mountain torrent hurtling from rock to rock, than a great sluggish river, broken very seldom by rapids. Ages of quiescence, often of actual stagnation, filled with the monotonous problems and toils of countless almost identical lives, have been punctuated by rare moments of racial adventure. Nay, even these few seemingly rapid events themselves were in fact often long-drawn-out and tedious. They acquire a mere illusion of speed from the speed of the narrative.

The receding depths of time and space, though they can indeed be haltingly conceived even by primitive minds, cannot be imaged save by beings of a more ample nature. A panorama of mountains appears to naïve vision almost as a flat picture, and the starry void is a roof pricked with light. Yet in reality, while the immediate terrain could be spanned in an hour’s walking, the sky-line of peaks holds within it plain beyond plain. Similarly with time. While the near past and the new future display within them depth beyond depth, time’s remote immensities are foreshortened into flatness. It is almost inconceivable to simple minds that man’s whole history should be but a moment in the life of the stars, and that remote events should embrace within themselves aeon upon aeon.

In your day you have learnt to calculate something of the magnitudes of time and space. But to grasp my theme in its true proportions, it is necessary to do more than calculate. It is necessary to brood upon these magnitudes, to draw out the mind toward them, to feel the littleness of your here and now, and of the moment of civilization which you call history. You cannot hope to image, as we do, such vast proportions as one in a thousand million, because your sense-organs, and therefore your perceptions, are too coarse-grained to discriminate so small a fraction of their total field. But you may at least, by mere contemplation, grasp more constantly and firmly the significance of your calculations.

Men of your day, when they look back into the history of their planet, remark not only the length of time but also the bewildering acceleration of life’s progress. Almost stationary in the earliest period of the earth’s career, in your moment it seems headlong. Mind in you, it is said, not merely stands higher than ever before in respect of percipience, knowledge, insight, delicacy of admiration, and sanity of will, but also it moves upward century by century ever more swiftly. What next? Surely, you think, there will come a time when there will be no further heights to conquer.

This view is mistaken. You underestimate even the foothills that stand in front of you, and never suspect that far above them, hidden by cloud, rise precipices and snow-fields. The mental and spiritual advances which, in your day, mind in the solar system has still to attempt, are overwhelmingly more complex, more precarious and dangerous, than those which have already been achieved. And though in certain humble respects you have attained full development, the loftier potencies of the spirit in you have not yet even begun to put forth buds.

Somehow, then, I must help you to feel not only the vastness of time and space, but also the vast diversity of mind’s possible modes. But this I can only hint to you, since so much lies wholly beyond the range of your imagination.

Historians living in your day need grapple only with one moment of the flux of time. But I have to present in one book the essence not of centuries but of aeons. Clearly we cannot walk at leisure through such a tract, in which a million terrestrial years are but as a year is to your historians. We must fly. We must travel as you do in your aeroplanes, observing only the broad features of the continent. But since the flier sees nothing of the minute inhabitants below him, and since it is they who make history, we must also punctuate our flight with many descents, skimming as it were over the house-tops, and even alighting at critical points to speak face to face with individuals. And as the plane’s journey must begin with a slow ascent from the intricate pedestrian view to wider horizons, so we must begin with a somewhat close inspection of that little period which includes the culmination and collapse of your own primitive civilization.