adult illnesses may come to be so manageable as to be hardly taken into account in the scheme of life. In this case it would seem that the generation would be far more able than now to "see its own work out," and that self-confidence, which is an efficient spring of energy, would be proportionately increased. To take a single instance from literature, Gibbon was only fifty-one when he completed the great work which is an epoch in historical literature. It had taken him twenty-seven years to perfect, and his expectation of life, as he himself tells us, allowed him only about fifteen years more.[1] He seems to have decided that, after taking the rest which was his just due, it would be too late for him to attempt any new task. Yet had his expectation of life been of thirty years instead of fifteen, his decision might have been different, and the world, had his life actually been prolonged, might have been the richer by a work showing Gibbon's ripest learning and maturest thought.
Against this consideration we must perhaps set the fact that a world in which the term of life is sensibly prolonged will be predominantly a world of old people. Unless we can assume, what is most unlikely, that the struggle for existence will become less and less severe as numbers multiply and the earth fills up, we must suppose that countries in the Temperate Zone at least will gradually approximate more and more to the stationary state. Society will accommodate itself to this by late marriages or by conjugal agreements to limit the number of children; and while the proportion of men and women over fifty is now, let us say, one in eight, it may easily come to be one in six. At this
- ↑ "The laws of probability … still allow about fifteen years."—Memoirs of my Life and Writings, by Gibbon, p. 127.