‘The Israel Letters’ (letters to Bob Silvers, from the New York Review of Books archive), ed. David Herman, Jewish Quarterly, May 2021, 67–87
What About Daphne? Correspondence with H. G. Nicholas - An interim working Glossary of Proper Names
‘The State of Psychology in 1936’ (draft version)
The Addiction of Russian Intellectuals to Historicism
More Flourishing - supplementary letters 1928-1946
More Enlightening - supplementary letters 1946-1960
Supplement to Flourishing: Letters 1928–1946, "What about Daphne?" Correspondence with H. G. Nicholas 1942–1945
Supplement to Affirming: 'More Explaining: Isaiah Berlin on his own ideas'
More Building - supplementary letters 1960-1975
More Affirming - supplementary letters 1975-1997
An online selection of the more significant letters to have emerged since the publication of Affirming: Letters 1975–1997 (London, 2015: Chatto and Windus; London, 2017, Pimlico)