Prof. Kagan, Donald, CLCV 205, Introduction to Ancient Greek History, Fall 2007, YALE Open Courses: Yale University, Classics (Accessed 23/09/2014), http://oyc.yale.edu/classics/clcv-205/lecture-19 License: Creative Commons BY-NC-SA 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. Professor Kagan argues that the war was not inevitable and that the Athenians under Pericles followed a policy of deterrence, which was aimed at peace. War broke out due to a number of factors that were avoidable. 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.