Sir Isaiah Berlin OM, FBA (6 June 1909 – 5 November 1997) was a British philosopher. He was born in Riga, Latvia, which at the time was a part of the Russian Empire. He was Jewish, and was the first Jew to win the prize of a fellowship at All Souls College, Oxford University.
Isaiah Berlin was an important person of the 20th century. People see him as an important thinker of Liberalist ideas. He was made a member of the Order of Merit and was a professor at the University of Oxford. He made a distinction between positive liberty and negative liberty. His most famous work is probably Two Concepts of Liberty (where he introduced this distinction.) He died 5 November 1997.