He meets them[19] by saying first of all: “There is a principle in the nature of human society by means of which everything seems to tend to its level,” when not interfered with; and the population of a country when left to itself does not seem to increase beyond the food. But in the second place, supposing things not to find their level in this way, the earth is wide and the evil day is far off. It may take myriads of centuries to till the untilled acres and to replenish the empty earth with people, and much may happen before then. In fact, he views the subject as many of us view the question of our coal supply. Before it is exhausted we may be beyond the need of it.[20] The earth itself may have collapsed with all its inhabitants. Don’t let us refuse a present blessing from fear of a remote future danger. Besides, it is not very hard to imagine a safeguard. Franklin says that “mind will one day become omnipotent over matter;”[21] why not over the matter of our own bodies? Does not the bodily health depend largely on the mind? “A merry heart goes all the day; Your sad tires in a mile, O!” The time may come when we shall be so full of liveliness that we shall not sleep, and so full of life that we shall not die. The _need_ for marriage will be superseded by earthly immortality, and the _desire_ for it by the development of intellect. On the renewed earth of the future there will be neither marrying nor giving in marriage, but we shall be as the angels. “The whole will be a people of men, and not of children. Generation will not succeed generation, nor truth have, in a certain degree, to recommence her career every thirty years. Other improvements may be expected to keep pace with those of health and longevity. There will be no war, no crimes, no administration of justice as it is called, and no government. Besides this, there will be neither disease, anguish, melancholy, nor resentment. Every man will seek with ineffable ardour the good of all.”[22]