According to Woodruff, what made Thucydides’s approach to events new was his attention to human dynamics as causal agents instead of, as in Homer’s work especially, causality being determined in the dynamic between superhuman forces and mortals. Thucydides was concerned especially with the force that ananke (compulsion) exerts on human decision-making. “[A]mbition, fear, and advantage” (36) are all pivotal parts of this compulsion—but none more than fear. The chief cause of the Peloponnesian war wasn’t how powerful Athens really was but how powerful Sparta perceived Athens to be and its fear of this perceived power. This fear made Sparta disinclined to pursue peaceful solutions to their and their allies’ grievances against Athens.

When superhuman forces are involved, humans may feel that they’re making choices—and may be making them—but the end is predetermined. Fate is unavoidable. Thucydides didn’t seem to believe that outcomes were inevitable in the same way. Instead, he suggested that when humans believe certain outcomes are inevitable, they behave in a way that brings those outcomes to pass; they may have other options but don’t recognize them as such. This is demonstrated repeatedly throughout Woodruff’s collection, perhaps most starkly in the contrast between Athens’s behavior in the Mytilenean dialogue of 427 BC and the Melos debate of 416, events with overlapping concerns that ended very differently.