If the history of Israel, from the time of Abraham to the coming of John the Baptist, was but a natural product, as easy to be accounted for as the mountains round about Jerusalem; why is it that the mountains still encompass the holy city; while we find no more men like Moses, David, and Isaiah to lead, to rule, and to prophesy? There are the same Judean hills and valleys. There rapidly flows the same historic Jordan. There grow the same grapes, the figs, and olives. There are the same holy mountains. There are the same dangerous rocks in the sea at Joppa. The physical conditions that made the corn and the honey and the cattle are there; and there still are found the corn, the honey, and the cattle. But no massive man like Moses ever more climbs Sinai to get law on tables of stone, or Pisgah, to see the promised land and die. No man after God’s own heart, like David, any more minds sheep, watches the stars, and writes poetry there. Never more do we find there a man like Isaiah, struggling on his knees in prayer that he may rise up to give his people the oracles of God. A shallow, degenerate and fickle people dwell amid the groves and the vines where once lived the great race which gave to men their ethics and the outlines of true religion. If the civilization of Rome, that reached such volume and force as to make her the mistress of the world, was as natural as the rising and falling of the tides, why is it that Rome is in ruins, while the tides continue to rise and fall? With no other aid than such as is afforded by natural law and physical force, we cannot solve this problem. Where monkeys grew once, monkeys grow to-day; where lions roamed once, lions roam to-day; where figs grew once, figs grow to-day. The same physical conditions, the same configuration of soil, the same degree of climate, produce uniform natural results from age to age. These may be counted on with the certainty of a coming eclipse, conditioned on varying conjunctions of the heavenly bodies. But we must pass from the level and range of soil, sky, climate, and physical conditions, to account for the fact that a country in one period of its history produces a Pericles, and, in another, a muddy-headed numskull; in one age an aristocracy of poets, artists, statesmen, philosophers, and orators; and in another, a listless swarm of stupid and secular cumberers of the ground. IV. The explanation of this question is to be found in the fact that man has a dual nature, a body and a spirit, by virtue of which he is individual and social. When the center of gravity is on the social side of human nature, the fortunes of man go up; when the center of gravity is on the individual side, the fortunes of man go down. On the individual side, he is the subject of physical law. On the social side, of moral law.