again, out of the surrounding darkness comes the blinding strokes of Fortune, unaccountable and unforeseen.' Thucydides' work indicates an influence from the teachings of the Sophists that contributes substantially to the thinking and character of his History. Possible evidence includes his skeptical ideas concerning justice and morality. There are also elements within the History—such as his views on nature revolving around the factual, empirical, and the non-anthropomorphic—which suggest that he was at least aware of the views of philosophers such as Anaxagoras and Democritus. There is also evidence of his knowledge concerning some of the corpus of Hippocratic medical writings. Thucydides was especially interested in the relationship between human intelligence and judgment, Fortune and Necessity, and the idea that history is too irrational and incalculable to predict. Critical interpretation Scholars traditionally viewed Thucydides as recognizing and teaching the lesson that democracies need leadership but that leadership can be dangerous to democracy. Leo Strauss (in The City and Man) locates the problem in the nature of Athenian democracy, about which, he argued, Thucydides was ambivalent. Thucydides's "wisdom was made possible" by the Periclean democracy, which had the effect of liberating individual daring, enterprise and questioning spirit; this liberation, by permitting the growth of limitless political ambition, led to imperialism and eventually, to civic strife. For Canadian historian Charles Norris Cochrane (1889–1945), Thucydides's fastidious devotion to observable phenomena, focus on cause and effect and strict exclusion of other factors anticipates twentieth-century scientific positivism. Cochrane, the son of a physician, speculated that Thucydides generally (and especially in describing the plague in Athens) was influenced by the methods and thinking of early medical writers such as Hippocrates of Kos. After World War II, classical scholar Jacqueline de Romilly pointed out that the problem of Athenian imperialism was one of Thucydides's preoccupations and situated his history in the context of Greek thinking about international politics. Since the appearance of her study, other scholars further examined Thucydides's treatment of realpolitik. Other scholars have brought to the fore the literary qualities of the History, which they see in the narrative tradition of Homer and Hesiod and as concerned with the concepts of justice and suffering found in Plato and Aristotle and questioned in Aeschylus and Sophocles. Richard Ned Lebow terms Thucydides "the last of the tragedians", stating that "Thucydides drew heavily on epic poetry and tragedy to construct his history, which not surprisingly is also constructed as