One of the prime dangers of civilization has always been its tendency to cause the loss of virile fighting virtues, of the fighting edge. When men get too comfortable and lead too luxurious lives, there is always danger lest the softness eat like an acid into their manliness of fibre. The barbarian, because of the very conditions of his life, is forced to keep and develop certain hardy qualities which the man of civilization tends to lose, whether he be clerk, factory hand, merchant, or even a certain type of farmer. Now I will not assert that in modern civilized society these tendencies have been wholly overcome; but there has been a much more successful effort to overcome them than was the case in the early civilizations. This is curiously shown by the military history of the Græco-Roman period as compared with the history of the last four or five centuries here in Europe and among nations of European descent. In the Grecian and Roman military history the change was steadily from a citizen army to an army of mercenaries. In the days of the early greatness of Athens, Thebes, and Sparta, in the days when the Roman Republic conquered what world it knew, the armies were filled with citizen soldiers. But gradually the citizens refused to serve in the armies, or became unable to render good service. The Greek states described by Polybius, with but few exceptions, hired others to do their fighting for them. The Romans of the days of Augustus had utterly ceased to furnish any cavalry, and were rapidly ceasing to furnish any infantry, to the legions and cohorts. When the civilization came to an end, there were no longer citizens in the ranks of the soldiers. The change from the citizen army to the army of mercenaries had been completed.