Lecture by Isaiah Berlin on 5 October 1964 to the conference on ‘One Hundred Years of Revolutionary Internationals’ held at Stanford University to mark the centenary of the First International Working Men’s Association The full text from which the lecture is loosely derived is included as ‘Marxism and the International in the Nineteenth Century’ in Berlin’s collection 'The Sense of Reality: Studies in Ideas and Their History', edited by Henry Hardy (London, 1996: Chatto and Windus; 2nd ed., Princeton, 2019: Princeton University Press)
