They have become since then considerably more brutal; the death penalty, which even in the last fifty years of last century was generally condemned, meets with no opposition any longer, and the cruelties of colonial wars, which fifty years ago, at least in Germany, would have made their authors impossible, are excused to-day—even glorified.
In any case, war among modern peoples ceases to play the rôle it did among the nomadic pastoral and hunting tribes. But if it produces cruelty and blood-thirstiness on the one hand, it shows itself on the other as a powerful weapon to strengthen the bonds within the family or society. The greater the dangers which threaten the individual, so much the more dependent does he feel himself upon his society, his family, his class, who alone with their joint forces can protect him. So much the greater the respect enjoyed by the virtues of unselfishness or a bravery which will risk life for the society. The more bloody the wars between tribe and tribe, the more will the system of selection have effect among them; those tribes will assert themselves best who have not only the strongest but also the cleverest, the bravest, the most self-sacrificing and best disciplined members to show. Thus war works in primitive times in the most various manners to strengthen the social instincts in men.
War, however, in the course of the social evolution alters its forms: also its causes change.
Its first cause, the uncertainty of the sources of food, ceases as soon as agriculture and the breeding of animals are more developed. But then begins a new cause of war: the possession of wealth. Not private property, but the tribal property. Side by side with tribes in fruitful regions we find others in unfruitful ones; adjoining nomadic, water-searching and poor shepherds, settled peasants to whom water had no longer value, whose farming produced plentiful surpluses, etc. War now becomes robbery and defence against robbery, and it has remained in essence the same till to-day.
