Michael Brown has written a brilliant, encyclopaedic but ultimately unconvincing book addressing an important subject that has for too long remained a closely guarded secret. A few minutes on Google Scholar will confirm that most references to the ‘Irish Enlightenment’ date from the last ten years. Scare quotes and question marks recur, emphasising the insecure status of this late arrival on the intellectual scene. The impact of the European Enlightenment on 18th-century Ireland has long been acknowledged, particularly since Marianne Elliott’s path-breaking studies of Wolfe Tone and the United Irishmen in the 1980s. It is common to contrast the enlightened (civic, anti-clerical, non-sectarian) republicanism of Tone and his comrades with the romantic nationalism of their 19th-century successors. Literacy in 18th-century Ireland was relatively advanced, especially in Ulster, where 70 per cent of men and 50 per cent of women could read. In recent