Every age, even those that seem at the first approach to be stationary, turns out to be transitional when we get to know more about it. Primitive societies are transformed by contacts and war. The China once conceived as immemorial and unchanging reveals itself as a long series of revolutions and wars. The apparent immobility of the medieval church becomes a succession of dissolving views; and perhaps the only generalization that may be true about this continual movement is that it becomes more swift and more hazardous as it proceeds, like the rapids of a great river hurrying to its fall. For there is something about the crisis in which we are at present involved which makes it at once more dangerous and more promising than those which have preceded. On the one hand, ideas are more powerful and more solvent; on the other-and this is a new fact in history the power put at our disposal by science opens possibilities, both of re-construction and ruin, such as have never before been at our command. The War has made the position clear to all who care about society, and even men of science are beginning at last, though slowly and sporadically, to peep out of their specialisms and consider, with apprehension and alarm, whither we are being carried by these new forces which we have not yet learned to control.