However deep and acrimonious are most contemporary political controversies, the merits of the federal system of government are recognized by adherents of widely different political doctrines and practices. In the most different conditions federalism has established itself as a useful principle for welding together into one political body groups and regions of great diversity. Neither geography nor linguistic, racial or religious differences have proved insurmountable obstacles to political unity. The federal system of government, in dividing powers between one central government and a number of local governments, allows for that diversity in unity which is so attractive a goal for human activities.