Those who sought to produce a super-brain embarked upon a great enterprise of research and experiment in a remote corner of the planet. It is unnecessary to tell in detail how they fared. Working first in secret, they later strove to persuade the world to approve of their scheme, but only succeeded in dividing mankind into two parties. The body politic was torn asunder. There were religious wars. But after a few centuries of intermittent bloodshed the two sects, those who sought to produce communicants and those who sought the super-brain, settled down in different regions to pursue their respective aims unmolested. In time each developed into a kind of nation, united by a religious faith and crusading spirit. There was little cultural intercourse between the two.

Those who desired to produce the super-brain employed four methods, namely selective breeding, manipulation of the hereditary factors in germ cells (cultivated in the laboratory), manipulation of the fertilized ovum (cultivated also in the laboratory), and manipulation of the growing body. At first they produced innumerable tragic abortions. These we need not observe. But at length, several thousand years after the earliest experiments, something was produced which seemed to promise success. A human ovum had been carefully selected, fertilized in the laboratory, and largely reorganized by artificial means. By inhibiting the growth of the embryo’s body, and the lower organs of the brain itself, and at the same time greatly stimulating the growth of the cerebral hemispheres, the dauntless experimenters succeeded at last in creating an organism which consisted of a brain twelve feet across, and a body most of which was reduced to a mere vestige upon the under-surface of the brain. The only parts of the body which were allowed to attain the natural size were the arms and hands. These sinewy organs of manipulation were induced to key themselves at the shoulders into the solid masonry which formed the creature’s house. Thus they were able to get a purchase for their work. The hands were the normal six-fingered hands of the Third Men, very greatly enlarged and improved. The fantastic organism was generated and matured in a building designed to house both it and the complicated machinery which was necessary to keep it alive. A self-regulating pump, electrically driven, served it as a heart. A chemical factory poured the necessary materials into its blood and removed waste products, thus taking the place of digestive organs and the normal battery of glands. Its lungs consisted of a great room full of oxidizing tubes, through which a constant wind was driven by an electric fan. The same fan forced air through the artificial organs of speech. These organs were so constructed that the natural nerve-fibres, issuing from the speech centres of the brain, could stimulate appropriate electrical controls so as to produce sounds identical with those which they would have produced from a living throat and mouth. The sensory equipment of this trunkless brain was a blend of the natural and the artificial. The optic nerves were induced to grow out along two flexible probosces, five feet long, each of which bore a huge eye at the end. But by a very ingenious alteration of the structure of the eye, the natural lens could be moved aside at will, so that the retina could be applied to any of a great diversity of optical instruments. The ears also could be projected upon stalks, and were so arranged that the actual nerve endings could be brought into contact with artificial resonators of various kinds, or could listen directly to the microscopic rhythms of the most minute organisms. Scent and taste were developed as a chemical sense, which could distinguish almost all compounds and elements by their flavour. Pressure, warmth, and cold were detected only by the fingers, but there with great subtlety. Sensory pain was to have been eliminated from the organism altogether; but this end was not achieved.

The creature was successfully launched upon life, and was actually kept alive for four years. But though at first all went well, in his second year the unfortunate child, if such he may be called, began to suffer severe pain, and to show symptoms of mental derangement. In spite of all that his devoted foster-parents could do, he gradually sank into insanity and died. He had succumbed to his own brain weight and to certain failures in the chemical regulation of his blood.

We may overlook the next four hundred years, during which sundry vain attempts were made to repeat the great experiment more successfully. Let us pass on to the first true individual of the fourth human species. He was produced in the same artificial manner as his forerunners, and was designed upon the same general plan. His mechanical and chemical machinery, however, was far more efficient; and his makers expected that, owing to careful adjustments of the mechanisms of growth and decay, he would prove to be immortal. His general plan, also, was changed in one important respect. His makers built a large circular ‘brain turret’ which they divided with many partitions, radiating from a central space, and covered everywhere with pigeon-holes. By a technique which took centuries to develop, they induced the cells of the growing embryonic brain to spread outwards, not as normal hemispheres of convolutions, but into the pigeon-holes which had been prepared for them. Thus the artificial ‘cranium’ had to be a roomy turret of ferro-concrete some forty feet in diameter. A door and a passage led from the outer world into the centre of the turret, and thence other passages radiated between tiers of little cupboards. Innumerable tubes of glass, metal, and a kind of vulcanite conveyed blood and chemicals over the whole system. Electric radiators preserved an even warmth in every cupboard, and throughout the innumerable carefully protected channels of the nerve fibres. Thermometers, dials, pressure gauges, indicators of all sorts, informed the attendants of every physical change in this strange half-natural, half-artificial system, this preposterous factory of mind.

Eight years after its inception the organism had filled its brain room, and attained the mentality of a new-born infant. His advance to maturity seemed to his foster-parents dishearteningly slow. Not till almost at the end of his fifth decade could he be said to have reached the mental standard of a bright adolescent. But there was no real reason for disappointment. Within another decade this pioneer of the Fourth Men had learned all that the Third Men could teach him, and had also seen that a great part of their wisdom was folly. In manual dexterity he could already vie with the best; but though manipulation afforded him intense delight, he used his hands almost wholly in service of his tireless curiosity. In fact, it was evident that curiosity was his main characteristic. He was a huge bump of curiosity equipped with most cunning hands. A department of state had been created to look after his nurture and education. An army of learned persons was kept in readiness to answer his impatient questions and assist him in his own scientific experiments. Now that he had attained maturity these unfortunate pundits found themselves hopelessly outclassed, and reduced to mere clerks, bottle-washers, and errand-boys. Hundreds of his servants were for ever scurrying into every corner of the planet to seek information and specimens; and the significance of their errands was by now often quite beyond the range of their own intelligence. They were careful, however, not to let their ignorance appear to the public. On the contrary, they succeeded in gaining much prestige from the mere mysteriousness of their errands.

The great brain was wholly lacking in all normal instinctive responses, save curiosity and constructiveness. Instinctive fear he knew not, though of course he was capable of cold caution in any circumstances which threatened to damage him and hinder his passionate research. Anger he knew not, but only an adamantine firmness in the face of opposition. Normal hunger and thirst he knew not, but only an experience of faintness when his blood was not properly supplied with nutriment. Sex was wholly absent from his mentality. Instinctive tenderness and instinctive group-feeling were not possible to him, for he was without the bowels of mercy. The heroic devotion of his most intimate servants called forth no gratitude, but only cold approval.

At first he interested himself not at all in the affairs of the society which maintained him, served his every whim, and adored him. But in time he began to take pleasure in suggesting brilliant solutions of all the current problems of social organization. His advice was increasingly sought and accepted. He became autocrat of the state. His own intelligence and complete detachment combined with the people’s superstitious reverence to establish him far more securely than any ordinary tyrant. He cared nothing for the petty troubles of his people, but he was determined to be served by a harmonious, healthy, and potent race. And as relaxation from the more serious excitement of research in physics and astronomy, the study of human nature was not without attractions. It may seem strange that one so completely devoid of human sympathy could have the tact to govern a race of the emotional Third Men. But he had built up for himself a very accurate behaviouristic psychology; and like the skilful master of animals, he knew unerringly how much could be expected of his people, even though their emotions were almost wholly foreign to him. Thus, for instance, while he thoroughly despised their admiration of animals and plants, and their religion of life, he soon learned not to seem hostile to these obsessions, but rather to use them for his own ends. He himself was interested in animals only as material for experiments. In this respect his people readily helped him, partly because he assured them that his goal was the further improvement of all types, partly because they were fascinated by his complete disregard, in his experimentation, of the common techniques for preventing pain. The orgy of vicarious suffering awakened in his people the long-suppressed lust in cruelty which, in spite of their intuitive insight into animal nature, was so strong a factor in the third human species.

Little by little the great brain probed the material universe and the universe of mentality. He mastered the principles of biological evolution, and constructed for his own delight a detailed history of life on earth. He learned, by marvellous archaeological technique, the story of all the earlier human peoples, and of the Martian episode, matters which had remained hidden from the Third Men. He discovered the principles of relativity and the quantum theory, the nature of the atom as a complex system of wave trains. He measured the cosmos; and with his delicate instruments he counted the planetary systems in much of the remote universe. He casually solved, to his own satisfaction at least, the ancient problems of good and evil, of mind and its object, of the one and the many, and of truth and error. He created many new departments of state for the purpose of recording his discoveries in an artificial language which he devised for the purpose. Each department consisted of many colleges of carefully bred and educated specialists who could understand the subject of their own department to some extent. But the coordination of all, and true insight into each, lay with the great brain alone.