The violence of the Islamic State, like the revolutionary violence of many who came before, might be best characterised by what Edmund Burke called ‘the sublime’: a willingness, indeed need and passion, for the ‘delightful terror’ of a sense of power, destiny, giving over to the infinite, ineffable and unknown. ‘No passion so effectually robs the mind of all its powers of acting and reasoning as fear,’ noted Burke in On the Sublime and the Beautiful (1756). ‘For fear being an apprehension of pain or death, it operates in a manner that resembles actual pain. Whatever therefore is terrible, with regard to sight, is sublime too…’