Why do we not bomb Rome? -- The development of the idea of Christendom -- The essential weakness of Christendom -- Heresies are experiments in man's unsatisfied search for truth -- The city of God -- The church salvages learning -- Charlemagne -- Black interlude -- The launching of the Crusades by the Church -- Christendom marches East -- A Catholic gentleman of 1440 -- Social inequality in the fourteenth and fifteenth centuries -- The dawn of social discontent -- The mental atmosphere before the Reformation -- How Henry VIII became a Protestant prince -- The counter Reformation -- The Jesuits -- The continual shrinkage of the Roman Catholic Church -- The struggle for Britain -- Shinto Catholicism -- Roman Catholicism in America -- The united Christian front -- The pretensions and limitations of Pope Pius XII.