And all the world will be _young_. The advances of medicine and surgery will have been such that most of the ailments and limitations of old age will have been eliminated. Life will be prolonged at its maximum of efficiency until death comes like sunset, and is met without pain and without reluctance. There will be no death from disease, and almost any sort of injury will be curable. And in a thousand years? What will become of our globe and its dominant race, if no great catastrophe occurs to stop its exponential curve of progress. But for that exponential curve and its tendency towards constant acceleration, a thousand years would be no great period to foretell. Life has become world-wide in the last thousand years. The intellectual outlook has increased with the area of travel and communication. Dogmas and shibboleths have lost their force. Art and science have been emancipated from their ecclesiastical fetters. But the immense leap made since coal came into its own as a world-force belongs to our own age. The exhaustion of the coal-fields might slow down progress for a time, but so long as mankind keeps its continuity, its past achievements and its rate of achievement will act as a stimulus and encouragement to further efforts, and new sources of energy will be discovered and utilized. And so we may feel justified in expecting continual progress for at least a thousand years. Can we imagine the result? A globe laid out like a huge garden, with a climate under perfect control; the internal heat of the earth brought to the surface and utilized as a source of never-failing energy. Portions of the interior of the earth reclaimed and made habitable; all machinery and sources of power wisely distributed and made instantly available for all legitimate purposes. The earth’s surface and the rippling ether in which it swims made into a vast playground of human thought and emotion, and all mankind throbbing in unison to every great thought. _The Earth will have become a sentient being._――It will be as closely unified and organized as the human individual himself. Mankind will be the “grey matter” of its brain. It may not resemble a sentient being high up in the scale of life, but it will be at least on the level of _protococcus_ or some other such humble plant-cell, which also consists of a minute proportion of material truly “alive” together with a greater bulk of stored foodstuff and waste products. Man will be conscious of his closer attachment to the earth. He will feel towards it a sort of personal patriotism, or the sort of loyalty that a veteran feels towards the Old Regiment. Specially exalted or sensitive people may even indulge in a kind of Geolatry animated by an old-world religious fervour. Can we focus our mental telescope into yet farther depths of time? A million years or so?