The cause of this military growth is very plain. The strongest nation has always been conquering the weaker; sometimes even subduing it, but always prevailing over it. Every intellectual gain, so to speak, that a nation possessed was in the earliest times made use of--was INVESTED and taken out--in war; all else perished. Each nation tried constantly to be the stronger, and so made or copied the best weapons; by conscious and unconscious imitation each nation formed a type of character suitable to war and conquest. Conquest improved mankind by the intermixture of strengths; the armed truce, which was then called peace, improved them by the competition of training and the consequent creation of new power. Since the long-headed men first drove the short-headed men out of the best land in Europe, all European history has been the history of the superposition of the more military races over the less military of the efforts, sometimes successful, sometimes unsuccessful, of each race to get more military; and so the art of war has constantly improved. But why is one nation stronger than another? In the answer to that, I believe, lies the key to the principal progress of early civilisation, and to some of the progress of all civilisation. The answer is that there are very many advantages--some small and some great--every one of which tends to make the nation which has it superior to the nation which has it not; that many of these advantages can be imparted to subjugated races, or imitated by competing races; and that, though some of these advantages may be perishable or inimitable, yet, on the whole, the energy of civilisation grows by the coalescence of strengths and by the competition of strengths. II.