Modern Socialism is, in its essence, the direct product of the recognition, on the one hand, of the class antagonisms, existing in the society of to-day, between proprietors and non-proprietors, between capitalists and wage-workers; on the other hand, of the anarchy existing in production. But, in its theoretical form, modern Socialism originally appears ostensibly as a more logical extension of the principles laid down by the great French philosophers of the eighteenth century. Like every new theory, modern Socialism had, at first, to connect itself with the intellectual stock-in-trade ready to its hand, however deeply its roots lay in material economic facts.The great men, who in France prepared men's minds for the coming revolution, were themselves extreme revolutionists. They recognized no external authority of any kind whatever. Religion, natural science, society, political institutions, everything, was subjected to the most unsparing criticism; everything must justify its existence before the judgment-seat of reason, or give up existence.