This reflexion brings us to the second theory that has a home in the life of bridges and roads. Other homes it has also, a vast number of them, for this theory belongs to the law of battle, the universal law of strife. In so far as the lower organisms are concerned, this law seems to be as permanent as the sun; we have no reason to suppose that its rule will ever be relaxed among birds, beasts, fishes, insects, or among other forms of life, such as competitive trees in a wood; but mankind is an eternal mystery, and none can say into what civilization of symphonic harmony the human race may be evolved by gradual improvements in the crowded struggle for existence. A hundred thousand years hence the competitions of human life may be like harmonious rivalries between notes in music, or like the wondrous orchestration that unites into a symphony of benign health all the communities of cells in a sound body. “All for Each, Each for All” is the social rule that Nature administers in her cellular civilizations; and she punishes with disease and death the bodies that rebel against her rule by developing harmful egotisms. Yet mankind has stereotyped a very different social rule, “Each for All, yet Each for Himself”; and what right have we to believe that this egotism, so long inherited, and continuously active, can change its nature gradually, till at last it will be as philharmonic as the cellular commonwealths forming a strong human body? At present this appears to be very improbable, but impossible we dare not call it, since every type of society is free to improve its own lot. So the law of strife in human affairs appeals to us not as a truth destined to last till doomsday, like the strife of carnivorous hunger, but as a theory which human life has not yet contradicted, but which in course of time may be tempered into a social art--a competitive harmony favourable to everybody. Yet even then, no doubt, inequalities of mind will be active in accordance with Nature’s law of infinite variation. Meanwhile, however, we have to accept history as mankind has made it. Strife has reigned everywhere; even the test of efficiency has been--not the survival of the finest natures, but--the survival of the least unfitted for a long battle against bad environments. Very often the delicate have the best characters and the most alert brains; and in times past the delicate died from hardships by myriads. Consider also the innumerable wars; slaughter and success have tried to go hand-in-hand together as boon companions. Every road through history is a changing procession of armies; every ancient bridge has a long story of battles. Indeed, bridges and roads have circulated all the many phases of strife that men have employed in civil rivalries, in mercantile competitions, in generative migrations, in roadside adventures with footpads and cut-throats, in fateful invasions, and in those missionary conquests which have given to religions their rival empires.