In this lecture, Professor Kagan focuses on the causes of the Peloponnesian War and the possible motivations for Thucydides' book, The History of the Peloponnesian War. Concerning the first point, Professor Kagan parts ways with Thucydides and argues that the war was not inevitable and that the Athenians under Pericles followed a policy of deterrence, which was aimed at peace. Similarly, he points out that there were a number of Spartans who did not want war as well. Therefore, according to this line of reasoning, war broke out due to a number of factors that were avoidable. Concerning the second point, Professor Kagan argues that Thucydides was a revisionist historian. In other words, Thucydides was writing not as a disinterested historian, but as a historian with a point to make, namely, that the war was inevitable and that Athens was only a democracy in name under Pericles. Finally, Professor Kagan acknowledges that his two points are debatable. Reading assignment: Pomeroy, Burstein, Donlan and Roberts. Ancient Greece. Oxford University Press: New York, 1999, pp. 287-329. Plutarch, The Rise and Fall of the Athens: Alcibiades. Thucydides, The Peloponnesian War, Books VI-VII.