There can be little doubt that, as Eduard Schwartz points out, the problem of the political sympathies of Thucydides can only be properly approached if it is remembered that his history in its present form was revised and possibly rewritten after the end of the Peloponnesian War. He was living in an atmosphere of défaitisme. Many of his contemporaries tended to glorify Sparta and her institutions, and to regard Athenian imperialism as a disastrous mistake. As a man of the older generation Thucydides felt it his duty to counteract this tendency by drawing attention to the real idealism which had inspired the Machtpolitik of the Periclean age, and by pointing to the benefits which the rule of Athens had conferred on the Greek world. The Preface to Book I may be regarded as a veiled apologia for the Athenian Empire, which had secured for Greece the freedom of intercourse which the writer holds to be essential alike for economic prosperity and for cultural development. Similarly the contrasts which Thucydides draws between the Athenian and the Spartan character, and the glorification of Athens which is the main subject of the Funeral Oration are inspired by the hope that the disillusioned Greeks of the early fourth century might come to realise that the ideals of Pericles and other Athenian imperialists had been not sordid but noble, and that Greece as a whole had derived benefits from the rule of Athens.