It is hard to find two more strikingly different intellectual personalities than the author of Trotsky’s classic biography and one of the “Russian Thinkers.” Comrade Isaac (Deutscher), as he was called by like-minded left-wing thinkers, was enamored with grandiose Hegelian-Marxist generalization and worshipped great men (a category in which he included Lenin, Stalin and Trotsky). Sir Isaiah (Berlin) was by nature skeptical, suspicious of utopianism, abhorred radicalism of any shade, and valued, more than anything else, the sense of reality. Deutscher was committed to monistic determinism, Berlin cherished agonistic pluralism.
During the Cold War years, these two thinkers, both born in the Russian empire to Jewish families with long rabbinical traditions, both émigrés (at different ages, to be sure) to England, both magnetized by Russian culture, came to embody incompatible visions of politics, history, and morality.
One important distinction needs to be made from the very outset: whereas Deutscher joined the underground Polish Communist Party in the 1920s, Berlin was never a member of a Leninist sect. True, comrade Isaac broke with the Stalinists and became an independent Marxist, an influential journalist and an acclaimed historian, but he never jettisoned a romanticized vision of early Bolshevism as a fountain of revolutionary hope. He admired intransigence, arduous pursuit of an ultimate revolutionary dream meant to fulfill a secret plan of History. For Berlin, this was nonsense. He abhorred any grandiose teleology and admired Alexander Herzen, a Russian thinker who opposed reckless radicalism. Like Herzen, in many respects his intellectual hero, Berlin refused to believe that history (not capitalized) develops in accordance with an esoteric libretto. Whereas he acknowledged, without sharing, Karl Marx’s philosophical insights, he regarded Lenin not only as a delusional Jacobin, but also as the founder of a despicable totalitarian experiment.