This paper reevaluates different readings of Thucydides, assisted by an analysis of the causes of the Peloponnesian War. The paper argues that Thucydides' own account of the outbreak of the Peloponnesian War hints at a more nuanced and pluralist methodology compared to the one that has traditionally been associated with his celebrated approach to the "truest reason" of the war. Relations between the "immediate" causes and the "truest reason" why war broke out can best be understood through the prism of a particular approach to levels of analysis, one that strives to master a more abstract understanding in order to transcend and harness the richness, the complexity, even the ambiguity of actual interactions, interactions that Thucydides understood so well. But the complexity and ambiguity of actual interactions do not seem to lead to war as an inevitable outcome. In the absence of a systematic approach to the relations between levels, harnessing the sensitive understanding of actual events preceding the war manifests itself almost as a response to an aporia: what Thucydides implies is that -given the participants' mind-sets, preconceptions, norms, culture, and interests -a number of conditions that must be analysed at a higher level of abstraction may render a certain outcome probable.