A great industrial nation may conquer the world in the span of a single life, but its Achilles' heel is time. Its children, what of them? The second and third generations, of what numbers and stuff will they be? How long can men thrive between walls of brick, walking on asphalt pavements, breathing the fumes of coal and of oil, growing, working, dying, with hardly a thought of wind, and sky, and fields of grain, seeing only machine-made beauty, the mineral-like quality of life. This is our modern danger — one of the waxen wings of flight. It may cause our civilization to fall unless we act quickly to counteract it, unless we realize that human character is more important than efficiency, that education consists of more than the mere accumulation of knowledge.