This first attack upon the nature of time involved an immense cooperative work, both theoretical and practical. It was from biology that the first hint had come that the past persisted. And it would be necessary to restate the whole of biology and the physical sciences in terms of the new idea. On the practical side it was necessary to undertake a great campaign of experiment, physiological and psychological. We cannot stay to watch this work. Millions of years passed by. Sometimes, for thousands of years at a spell, temporal research was the main preoccupation of the race; sometimes it was thrust into the background, or completely ignored, during epochs which were dominated by other interests. Age after age passed, and always the effort of man in this sphere remained barren. Then at last there was a real success.

A child had been selected from among those produced by an age-long breeding enterprise, directed towards the mastery of time. From infancy this child’s brain had been very carefully controlled physiologically. Psychologically also he had been subjected to a severe treatment, that he might be properly schooled for his strange task. In the presence of several scientists and historians he was put into a kind of trance, and brought out of it again, half an hour later. He was then asked to give an account ‘telepathically’ of his experiences during the trance. Unfortunately he was now so shattered that his evidence was almost unintelligible. After some months of rest he was questioned again, and was able to describe a curious episode which turned out to be a terrifying incident in the girlhood of his dead mother. He seemed to have seen the incident through her eyes, and to have been aware of all her thoughts. This alone proved nothing, for he might have received the information from some living mind. Once more, therefore, and in spite of his entreaties, he was put into the peculiar trance. On waking he told a rambling story of ‘little red people living in a squat white tower’. It was clear that he was referring to the Great Brains and their attendants. But once more, this proved nothing; and before the account was finished the child died.

Another child was chosen, but was not put to the test until late in adolescence. After an hour of the trance, he woke and became terribly agitated, but forced himself to describe an episode which the historians assigned to the age of the Martian invasions. The importance of this incident lay in his account of a certain house with a carved granite portico, situated at the head of a waterfall in a mountain valley. He said he had found himself to be an old woman, and that he, or she, was being hurriedly helped out of the house by the other inmates. They watched a formless monster creep down the valley, destroy their house, and mangle two persons who failed to get away in time. Now this house was not at all typical of the Second Men, but must have expressed the whim of some freakish individual. From evidence derived from the boy himself, it proved possible to locate the valley with reference to a former mountain, known to history. No valley survived in that spot; but deep excavations revealed the ancient slopes, the fault that had occasioned the waterfall, and the broken pillars.

This and many similar incidents confirmed the Fifth Men in their new view of time. There followed an age in which the technique of direct inspection of the past was gradually improved, but not without tragedy. In the early stages it was found impossible to keep the ‘medium’ alive for more than a few weeks after his venture into the past. The experience seemed to set up a progressive mental disintegration which produced first insanity, then paralysis, and, within a few months, death. This difficulty was at last overcome. By one means and another a type of brain was produced capable of undergoing the strain of supra-temporal experience without fatal results. An increasingly large proportion of the rising generation had now direct access to the past, and were engaged upon a great re-statement of history in relation to their first-hand experience; but their excursions into the past were uncontrollable. They could not go where they wanted to go, but only where fate flung them. Nor could they go of their own will, but only through a very complicated technique, and with the cooperation of experts. After a time the process was made much easier, in fact, too easy. The unfortunate medium might slip so easily into the trance that his days were eaten up by the past. He might suddenly fall to the ground, and lie rapt, inert, dependent on artificial feeding, for weeks, months, even for years. Or a dozen times in the same day he might be flung into a dozen different epochs of history. Or, still more distressing, his experience of past events might not keep pace with the actual rhythm of those events themselves. Thus he might behold the events of a month, or even a lifetime, fantastically accelerated so as to occupy a trance of no more than a day’s duration. Or, worse, he might find himself sliding backwards down the vista of the hours and experiencing events in an order the reverse of the natural order. Even the magnificent brains of the Fifth Men could not stand this. The result was maniacal behaviour, followed by death. Another trouble also beset these first experimenters. Supra-temporal experience proved to be like a dangerous and habit-forming drug. Those who ventured into the past might become so intoxicated that they would try to spend every moment of their natural lives in roaming among past events. Thus gradually they would lose touch with the present, live in absentminded brooding, fail to react normally to their environment, turn socially worthless, and often come actually to physical disaster through inability to look after themselves.

Many more thousands of years passed before these difficulties and dangers were overcome. At length, however, the technique of supra-temporal experience was so perfected that every individual could at will practise it with safety, and could, within limits, project his vision into any locality of space-time which he desired to inspect. It was only possible, however, to see past events through the mind of some past organism, no longer living. And in practice only human minds, and to some extent the minds of the higher mammals, could be entered. The explorer retained throughout his adventure his own personality and system of memory. While experiencing the past individual’s perceptions, memories, thoughts, desires, and in fact the whole process and content of the past mind, the explorer continued to be himself, and to react in terms of his own character, now condemning, now sympathizing, now critically enjoying the spectacle.

The task of explaining the mechanism of this new faculty occupied the scientists and philosophers of the species for a very long period. The final account, of course, cannot be presented save by parable; for it was found necessary to recast many fundamental concepts in order to interpret the facts coherently. The only hint that I can give of the explanation is in saying, metaphorically of course, that the living brain had access to the past, not by way of some mysterious kind of racial memory, nor by some equally impossible journey up the stream of time, but by a partial awakening, as it were, into eternity, and into inspection of a minute tract of space-time through some temporal mind in the past, as though through an optical instrument. In the early experiments the fantastic speeding, slowing, and reversal of the temporal process resulted from disorderly inspection. As a reader may either skim the pages of a book, or read at a comfortable pace, or dwell upon one word, or spell the sentence backwards, so, unintentionally, the novice in eternity might read or misread the mind that was presented to him.

This new mode of experience, it should be noted, was the activity of living brains, though brains of a novel kind. Hence what was to be discovered ‘through the medium of eternity’ was limited by the particular exploring brain’s capacity of understanding what was presented to it. And, further, though the actual supra-temporal contact with past events occupied no time in the brain’s natural life, the assimilating of that moment of vision, the reduction of it to normal temporal memory in the normal brain structures, took time, and had to be done during the period of the trance. To expect the neural structure to record the experience instantaneously would be to expect a complicated machine to effect a complicated readjustment without a process of readjusting.

The new access to the past had, of course, far-reaching effects upon the culture of the Fifth Men. Not only did it give them an incomparably more accurate knowledge of past events, and insight into the motives of historical personages, and into large-scale cultural movements, but also it effected a subtle change in their estimate of the importance of things. Though intellectually they had, of course, realized both the vastness and the richness of the past, now they realized it with an overwhelming vividness. Matters that had been known hitherto only historically, schematically, were now available to be lived through by intimate acquaintance. The only limit to such acquaintance was set by the limitations of the explorer’s own brain-capacity. Consequently the remote past came to enter into a man and shape his mind in a manner in which only the recent past, through memory, had shaped him hitherto. Even before the new kind of experience was first acquired, this race had been, as was said, peculiarly under the spell of the past; but now it was infinitely more so. Hitherto the Fifth Men had been like stay-at-home folk who had read minutely of foreign parts, but had never travelled; now they had become travellers experienced in all the continents of human time. The presences that had hitherto been ghostly were now presences of flesh and blood seen in broad daylight. And so the moving instant called the present appeared no longer as the only, and infinitesimal, real, but as the growing surface of an everlasting tree of existence. It was now the past that seemed most real, while the future still seemed void, and the present merely the impalpable becomingness of the indestructible past.

The discovery that past events were after all persistent, and accessible, was of course for the Fifth Men a source of deep joy; but also it caused them a new distress. While the past was thought of as a mere gulf of non-existence, the inconceivably great pain, misery, baseness, that had fallen into that gulf, could be dismissed as done with; and the will could be concentrated wholly on preventing such horrors from occurring in the future. But now, along with past joy, past distress was found to be everlasting. And those who, in the course of their voyaging in the past, encountered regions of eternal agony, came back distraught. It was easy to remind these harrowed explorers that if pain was eternal, so also was joy. Those who had endured travel in the tragic past were apt to dismiss such assurances with contempt, affirming that all the delights of the whole population of time could not compensate for the agony of one tortured individual. And anyhow, they declared, it was obvious that there had been no preponderance of joy over pain. Indeed, save in the modern age, pain had been overwhelmingly in excess.

So seriously did these convictions prey upon the minds of the Fifth Men, that in spite of their own almost perfect social order, in which suffering had actually to be sought out as a tonic, they fell into despair. At all times, in all pursuits, the presence of the tragic past haunted them, poisoning their lives, sapping their strength. Lovers were ashamed of the delight in one another. As in the far-off days of sexual taboo, guilt crept between them, and held their spirits apart even while their bodies were united.