"Burke argued that all the nations of Europe had evolved from some fusion of Roman law, Christian morality, and Teutonic customs and manners, and that this complex of nations constituted a "commonwealth of Europe," the product of slow historical development over many centuries. Burke did not believe that history, as "the known march of the ordinary providence of God," contained any law of necessary progress, but he did believe that improvements in the civil-social life of the Europeans could and did continue to occur. He regarded all the basic institutions of society—family, church, state, schools, guilds, commercial organizations—all corporate bodies, as the necessary instrumental means for the full development of human nature in its spiritual and temporal dimensions. All such institutions were "natural"; that is, normal for man, the product of his will and reason, created artfully for his improvement. Burke summarized his defense of the institutions of civilization in an epigram: "Art is man's nature.""