How many pages of print need be devoted to an event that amounts to no more than a small footnote, if that, in the history of British academic life? In the case of the dueling protagonists of Isaac & Isaiah, a new book by the British historian and novelist David Caute, the unfortunate answer is: quite a few. Luckily, there is much else of inadvertent interest in the story Caute tells.

Both Isaiah Berlin (1909-1997) and Isaac Deutscher (1907-1967) were born to Jewish parents in Eastern Europe, but otherwise they had little in common. Berlin, who arrived in England as a schoolboy, eventually became a central and much celebrated figure of the British intellectual and academic establishment and was knighted in 1957. Deutscher, who arrived in his thirties, established himself within a few years as a well-known biographer and political commentator and a self-proclaimed exemplar of the human type known as the “non-Jewish Jew,” a term he may have coined.

Caute presents his chosen pair as the “most influential scholars of cold-war politics.” This is not accurate. Berlin, whose many interests included Russian social and political thought, was not and never claimed to be an expert in Soviet politics—the field that preoccupied Deutscher almost entirely. Nor was Berlin ever a political activist, while Deutscher, by contrast, had been a member of the Polish Communist party, later a Trotskyite, and thereafter a faithful fellow traveler and well-wisher of the Soviet Union. Finally, although Deutscher acquired a remarkable mastery of the English language—in a 1967 review of one of his biographies, I noted not only his forceful style but his unique ability to make his protagonists come alive—whether he was a scholar by inclination or accomplishment has remained a matter of controversy to this day....