Given that Aron's lectures were published in French and never translated, there isn't much English language discussion to be found. That said, according to Perrine Simon-Nahum, "The 1965 Gifford Lectures and a series of 1967 talks published as La Conscience historique dans la pensée et dans l’action presented Aron with an occasion to revisit his theory of history and to continue his engagement with Thucydides' analysis of political action and warfare." [Colen and Dutartre-Michaut, eds., The Companion to Raymond Aron, p. 114.]