What is the main conflict in The World's Great Speeches by Lewis Copeland?

The book is presented as a series of speeches, ranging from Ancient Greece to the 1990s. These speeches include such famous orators as Pericles and Mark Antony, though the latter is actually the speech written by Shakespeare for his play, "Julius Caesar." These earliest offerings cover several topics but many focus on the deaths of soldiers or important people. As the geographic locations of the orators change to Europe, the topics change only slightly. Martin Luther addresses his judges regarding the charge that he has betrayed the Catholic Church with his teachings. Those teachings become the basis for the Protestant movement and Luther, probably knowing that he is facing a death sentence, stands by his words. John Calvin also speaks of religious ideals before the topic moves back to war with Napoleon.