What Does Nietzsche Owe Thucydides?

Thucydides was one of Nietzsche's most important intellectual influences, but the extent of Nietzsche's debt to Thucydides has not been fully grasped. Here I consider the accounts of particular passages of Thucydides's History of the Peloponnesian War that appear in Nietzsche's published writings. I argue that while the views on justice that Nietzsche claims to find in Thucydides differ somewhat from the doctrine of the History, Thucydides's views in moral psychology likely had a significant effect on Nietzsche's accounts of wishful thinking and "idealism" in philosophy. I then show how the virtues of factuality and intellectual courage that Nietzsche ascribes to Thucydides in Twilight of the Idols can be understood through appeal to the psychological theories found in Thucydides's History. I conclude by discussing Nietzsche's virtue epistemology and the ideal of the magnanimous philosopher that appears in the first section of On the Genealogy of Morals.