The thinkers of the classical world were very concerned with war, ideas on the reasons for war, its justifications, and its accepted limits. ‘Thinking about war’ considers what these thoughts tell us about the past and also about modern discussions and attitudes. Herodotus and Thucydides, two great historians of classical Greece, took war as a central theme in their rhetoric. Does the failure of Greeks to produce a theory on the just war suggest that they thought war was a normal state of humanity? What did the Romans think about a just war? What did the Christians under Rome think about war? What did Augustine have to say about war?