Polybius is our starting point because he is obviously, explicitly and unashamedly a moral-didactic historian. He repeatedly stresses that the purpose of studying the past is to learn lessons that will be of use in the present. This is recognised by most Polybius scholars, but there is a widespread tendency to think of these lessons as purely practical rather than moral: Pédech, in his monumental La Méthode Historique de Polybe, devotes chapters to Polybius’ notions of psychology and his rhetorical method of comparison, but only touches on his moral didacticism in passing; Walbank says that Polybius saw history as ‘a way to attain practical ends by learning lessons’; Sacks in his monograph on Polybius’ views on historiography argues that his practical didacticism so far outweighs his moral didacticism that the latter ‘ought to be considered random digressions without historiographical import’; and even two otherwise excellent – and very different – more recent monographs on Polybius, by McGing and Maier, largely ignore the moralising aspect. In this way the moralist Polybius has been played down in favour of the image of the practical, pragmatic and often rather cynical Polybius, who wrote a ‘handbook for statesmen’ with digressions on such amoral topics as fire-signalling and how to calculate the needed length of scaling ladders.

This image, with which the present study wants to take serious issue, is often coupled with the equally dubious idea that Polybius wrote his work partly to justify his ‘collaboration’ with Rome and only used moral outrage to cloak his partisanship. There is no denying that Polybius shows political bias: he is obviously sympathetic to Achaea and scornful of the Aetolians, and also often sides with Rome against its opponents. However, his bias is commonly exaggerated: Polybius is not simply a blind approver of everything Roman. Furthermore, as already argued in the Introduction, moral views and political views do not exist in separate spheres, but feed off each other. Polybius supported the Achaean League because he had been born into its leading circles, but also because he believed that the League's laws were the most morally just of any political organisation he knew (2.38).