This essay explores the intellectual ties between Lev Tolstoy and the Nobel Prize winning pathologist Ilya Mechnikov. In Tolstoy's essays, letters, and diary entries he was notoriously critical of contemporary scientific study and its lack of a moral component. Beginning in the late 1880s he engaged in a virtually unknown polemic with Mechnikov about science and religion that culminated in a face-to-face meeting the year before Tolstoy's death. Despite Tolstoy's expressed disdain for Mechnikov's theories, in his final novel, Resurrection (1899), Tolstoy used Mechnikov's phagocytic theory as a metaphoric basis for the novel's moral philosophy. Moving beyond his earlier family ideal, he made phagocytes the model for a broader and more impersonal ideal of human unity. Thus, in Resurrection Tolstoy found a way to give moral meaning to science, just as he had called for in his journalistic writing.