It is tempting to imagine that we can discover this by a mere calculation of the total expenditure on all work carried on in the district and comparing this either with the number of Christians and their relative wealth or poverty, or simply with the contribution which they actually make, concluding that the difference between their contribution, or their estimated power to give, and the cost of the work carried on in the area is the difference between their power to supply their needs and their real needs. But foreign funds are largely spent upon things which, however excellent they may be in themselves, are not really _necessary_ for the religious life of the Christians, such as missionaries' salaries, high schools, colleges, medical institutions, and expensive buildings. Consequently to know the total expenditure in the area is not to know the necessary expenditure. The native Church might maintain its life and conquer the whole district without spending in actual money a tithe of that which we spend on providing the people with medicine and education and buildings and foreign missionaries. Yet the question cannot be avoided. Missionaries all over the world carefully count every penny which the converts subscribe, and search diligently for some new method of doubling it, in order to lead their converts towards the goal of self-support. What that goal is we do not know. We cannot tell how far the Christians can supply their own needs, if we do not know what the needs really are. And that we do not know. In a certain very real sense Christians can always provide what is necessary for their religious life. They could all always be self-supporting, if we did not invent needs and insist upon them; and what we insist upon depends entirely upon the school in which we were brought up. The standard set, as we have already explained, is purely arbitrary.