There remains, however, a class of wars which escapes this condemnation; and about them difficult moral problems may be raised. We can hardly deny to a growing and civilised nation the right to expand at the expense of barbarous hunters and nomads. No one would suggest that the Americans ought to give back their country to the Indians, or that Australia should be abandoned to the aborigines. But were the Anglo-Saxons justified in expropriating the Britons, and the Spaniards the Aztecs? There is room for differences of opinion in these cases; and a very serious problem may arise in the future, as to whether the European races are morally justified in using armed force to restrict Asiatic competition. As a general principle, we must condemn the expropriation of any nation which is in effective occupation of the soil. The popular estimate of superior and inferior races is thoroughly unchristian and unscientific, as is the prejudice against a dark skin. The opinion that a nation which is increasing in population has a right to expel the inhabitants of another country to make room for its own emigrants is surely untenable. If it justifies war at all, it sanctions a war of extermination, which would attain its objects most completely by massacring girls and young women. The pressure of population is a real cause of war; but the moral is, not that war is right, but that a nation must cut its coat according to its cloth, and limit its numbers. Unless we justify wars of extermination, war has no biological sanction, and Christianity is not flying in the face of nature by condemning it. On the contrary, by condemning every form of parasitism, it indicates the true path of evolution. It is equally right in rejecting the purely economic valuation of human goods. The 'economic man' does not exist in nature; he is a fictitious creature who is responsible for a great deal of social injustice. Some modern economists, like Mr. Hobson, would substitute for the old monetary standards of production and distribution an attempt to estimate the 'human costs' of labour. Creative work involving ingenuity and artistic qualities is not 'costly' at all, unless the hours of labour, or the nervous strain, exceed the powers of the worker. More monotonous work is not costly to the worker if the day's labour is fairly short, or if some variety can be introduced. The human cost is greatly increased if the worker thinks that his labour is useless, or that it will only benefit those who do not deserve the enjoyment of its fruits. Work which only produces frivolous luxuries is and ought to be unwelcome to the producer, even if he is well paid. It must also be emphasised that worry and anxiety take the heart out of a man more than anything else. Security of employment greatly reduces the 'human cost' of labour. These considerations are comparatively new in political economy. They change it from a highly abstract science into a