The concurrence of two elements is necessary for bringing about a revolution; and by revolution I do not mean the street warfare, nor the bloody conflicts of two parties—both being mere incidents dependent upon many circumstances—but the sudden overthrow of institutions which are the outgrowths of centuries past, the sudden uprising of new ideas and new conceptions, and the attempt to reform all political and economical institutions in a radical way—all at the same time. Two separate currents must converge to come to that result: a widely spread economic revolt, tending to change the economical conditions of the masses, and a political revolt, tending to modify the very essence of the political organisation—an economical change, supported by an equally important change of political institutions.