For most of his life his reputation as a writer lagged behind his actual output, much of which was in the form of occasional essays (‘I am like a taxi: I have to be hailed’), often published obscurely. Comparatively little had appeared in book form – principally Karl Marx, The Hedgehog and the Fox (a long essay on Tolstoy’s view of history), and the collection Four Essays on Liberty, which included his inaugural lecture. But then in 1976 came Vico and Herder, and shortly thereafter four volumes of collected essays (1978–80). These books gave the lie to a remark made by his friend Maurice Bowra when Berlin was appointed to the Order of Merit in 1971: ‘Though like Our Lord and Socrates he does not publish much, he thinks and says a great deal and has had an enormous influence on our times.’ Other volumes followed in the 1990s, including two devoted to work he had left unpublished when it was first written, and The Proper Study of Mankind, a retrospective anthology of his work published early in the year of his death.

By contrast with Bowra’s case, a good deal of Berlin’s way of speaking is captured, happily, in his published work, which is imbued with his personality and sets forth his cardinal intellectual preoccupations with the greatest clarity and fecundity, if often through the medium of his enquiries into the ideas of others. One of the most attractive characteristics of his writing is that he is never merely the detached scholar, never forgetful that the point of the enquiry, in the end, is to increase understanding and moral insight. Since, as another friend, Noel Annan, has put it ‘He will always use two words where one will not do’, his message – a notion he would have hated – is impossible to summarise without losing all of its characteristic mode of expression. But its central content can be baldly stated.