Sir Isaiah Berlin OM, CBE, FBA (6 June 1909 – 5 November 1997) was a Russo-British Jewish social and political theorist, philosopher and historian of ideas, "thought by many to be the dominant scholar of his generation". He excelled as an essayist, conversationalist and raconteur; and as a brilliant lecturer who improvised, rapidly and spontaneously, richly allusive and coherently structured material.