Sir Isaiah Berlin OM CBE FBA (6 June 1909 – 5 November 1997) was a Russian-British social and political theorist, philosopher, and historian of ideas. Although he became increasingly averse to writing for publication, his improvised lectures and talks were sometimes recorded and transcribed, and many of his spoken words were converted into published essays and books, both by himself and by others, especially his principal editor from 1974, Henry Hardy.