The purpose of this essay is to elucidate the personal religious views of Maximilien Robespierre and to see how these interlocked with the formation of religious policy during the Revolution, particularly with the establishment of the cult of the Supreme Being. It is not special pleading to say at the outset that this is not a straightforward task. Robespierre has always been a controversial figure, and in no area has historical opinion been more divided than with respect to religion. Academic debate came to a peak in the bitter arguments between Alphonse Aulard and his one-time disciple, Albert Mathiez. ‘The person of Robespierre has been so grossly misrepresented during the last twenty years, even by republican historians,’ wrote the latter in 1910, with Aulard in mind, ‘that to talk now of the “Incorruptible's” religious ideas would appear a rash undertaking.’ Although less fierce than hitherto, disagreement between historians over Robespierre and religion persists. Indeed, it is unlikely ever to be finally resolved. The reason for this lies in the nature and availability of the surviving evidence. We lack the diaries, private papers, letters, reminiscences and epistolatory confidences that might clarify once and for all Robespierre's religious opinions and the motives behind the formation of revolutionary religious policies. To be sure, we have his public writings and speeches, although these, with their dense thickets of prose, can be as wearying to read now as they were to hear two centuries ago. They were, of course, drafted with the aim of influencing others rather than with the intention of revealing the author's innermost feelings.