Some students of ancient history treat Thucydides as an "authority," not a "source," creating an obstinate resistance to criticism and a readiness to explain away his apparent omissions and distortions. Others, especially students of ancient literature, focus attention on "understanding Thucydides as a whole" through the internal relationships -echoes, analogies, and symmetries, as well as contradictions - which can be uncovered in his work, rather than through its external relationships with events. The apparent omissions, distortions, and incoherencies should remind us (...) that Thucydides, like all pioneers, imported irrelevant preconceptions or had not yet formed necessary conceptions to do a truly systematic inquiry. Criticism of Thucydides should thus be more pluralistic; the reasons why one passage is unsatisfactory and perplexing may be different in kind from the reasons which hold in another, and two or more reasons may account for the difficulties in the same passage. (shrink)