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.
— THEODORE ROOSEVELT