This chapter considers the different conservative reactions to the mid-century European revolutions and the emergence of mass politics. It also examines the ways in which conservatism changed over time from the anti-revolutionary creed of 1848 to the more complex, intellectualised and yet irrational forms it had adopted by the end of the century. These reactions focus on British, American and European forms of conservative thought. Southern conservatism developed in very different political and economic contexts from those in which nineteenth-century British conservatism took root, though the two movements shared ideological positions and social instincts. From the 1870s, European conservatism became increasingly anti-rational and vulgar towards the end of the century, emphasising instinctive behaviour, intuition rather than reason, and the subconscious. H. Stuart Hughes has referred to this as 'the revolt against positivism'. In Maurice Barrás the spirit of conservative irrationalism found a characteristic proponent among fin-de-siàcle men of letters.