This article investigates social critique in Thucydides’ History of thePeloponnesian War. Two famous Thucydidean episodes are in focus:the Mytilenean Debate in Book III and the Melian Dialogue in BookV of the History. These episodes are interpreted here as inquiriesassuming the shape of subversive and transformative socialcriticism: immanent critique. Immanent critique aims at shiftinghorizons of meaning in social contexts, and the philosopherspracticing this kind of social criticism understand themselves asphysicians of a failing society. In Thucydides’ work, a particularobject of criticism is formed by varying dominant social and moralordering principles. In the Mytilenean Debate, it is the principle ofexpediency (τò ξυ΄μφορον) that rules, whereas in the MelianDialogue the governing normative ordering principle is that ofsafety and survival (σωτηρíα). In each episode, a contendingperspective is introduced for the purpose of undermining thedominating principle.