Yet this problem is fundamental. Payment takes on a different aspect when, instead of being expressed in terms of milliards and as a liability of the transitory abstraction, it is translated into a demand for a definite sum from a specific individual. This stage is not yet reached, and until it is reached the full intrinsic difficulty will not be felt. For at this stage the struggle ceases to be primarily one between the Allies and the German Government and becomes a struggle between different sections and classes of Germans. The struggle will be bitter and violent, for it will present itself to each of the contesting interests as an affair of life and death. The most powerful influences and motives of self–interest and self–preservation will be engaged. Conflicting conceptions of the end and nature of Society will be ranged in conflict. A Government which makes a serious attempt to cover its liabilities will inevitably fall from power. (3) What relation do the demands bear to the third test of capacity, the present income of the German people? A burden of 70 milliard paper marks (if we may, provisionally, adopt that figure as the basis of our calculations) amounts, since the population is now about 60 millions, to 1170 marks per head for every man, woman, and child. The great changes in money values have made it difficult, in all countries, to obtain estimates of the national income in terms of money under the new conditions. The Brussels Conference of 1920, on the basis of inquiries made in 1919 and at the beginning of 1920, estimated the German income per head at 3900 paper marks. This figure may have been too low at the time, and, on account of the further depreciation of the mark, is certainly too low now. A writer in the _Deutsche Allgemeine Zeitung_ (Feb. 14, 1921), working on the statistics of statutory deductions from wages and on income–tax, arrived at a figure of 2333 marks per head. This figure also is likely to be too low, partly because the statistics must mainly refer to earlier dates when the mark was less depreciated, and partly because all such statistics necessarily suffer from evasions. At the other extreme lies the estimate of Dr. Albert Lansburgh, who, by implication (_Die Bank_, March 1921), estimated the income per head at 6570 marks.[50] Another recent estimate is that of Dr. Arthur Heichen in the _Pester Lloyd_ (June 5, 1921), who put the figure at 4450 marks. In a newspaper article published in various quarters in August 1921 I ventured to adopt the figure of 5000 marks as the nearest estimate I could make. In fixing on this figure I was influenced by the above estimates, and also by statistics as to the general level of salaries and wages. Since then I have looked into the matter further and am still of the opinion that this figure was high enough for that date.