INDIRECT ENCROACHMENT ON FEDERAL AUTHORITY 931 intelligence to the enterprise of forecasting and evaluating the practical results from differing courses of action, and of choosing that course which leads to the result preferred. Marshall pursued a vain hope in thinking it possible to "measure the power of taxation residing in the State by the extent of sovereignty which the people of a single State possess and can confer on its goverrmient." We can, however, if we find it necessary, measure to a considerable degree the extent of sovereignty residing in the state, by finding what the ojficial interpreters of the Constitution permit the state to do in the exercise of the power of taxation and of other governmental func- tions. "Sovereignty" is a way of stating results rather than a means of reaching them. Thomas Reed Powell. Columbia University.