Two contrasting pictures emerge from the appraisals of Joseph Stalin written by his revolutionary colleagues and competitors. On the one hand, there was, for example, a fellow Georgian who knew Stalin in his early years as a Bolshevik organizer and who describes “his unquestionably greater energy, indefatigable capacity for hard work, unconquerable lust for power and above all his enormous particularistic organizational talent.” On the other, there are the unflattering judgments of his most virulent opponents in the Bolshevik hierarchy, from Leon Trotsky, who thought Stalin the “outstanding mediocrity of our party,” to Lev Kamanev, who considered the man who came to preside over the vast expanses of the reconstituted Russian empire “a small-town politician.”

For Stephen Kotkin, the John P. Birkelund professor in history and international affairs at Princeton University, it is clearly the first assessment that comes closer to the truth. In “Stalin. Volume I: Paradoxes of Power, 1878-1928,” a masterly account that is the first of a projected three-volume study, Kotkin paints a portrait of an autodidact, an astute thinker, “a people person” with “surpassing organizational abilities; a mammoth appetite for work; a strategic mind and an unscrupulousness that recalled his master teacher, Lenin.”...