It must be admitted that the attempt to build such a science is confronted by many difficulties. The causal sequences which lead up to results in the sphere of the social sciences are far more complex than are parallel sequences in the natural sciences. Again, the isolation of single causal tendencies, by the experimental method is well-nigh impossible in the social sciences. Thirdly, there is the difficulty of co-ordinating the divergent conclusions which are the fruit of specialized research in the different branches of the science of society.