Against a background of graft and social climbing and insincerity, the figure of Dr. Max Gottlieb stands out as a pure scientist and a seeker of truth. Lewis modeled him after Jacques Loeb, a prominent United States scientist of the time, born in Germany. Some critics find Gottlieb the novel's most memorable character. Professor Grebstein considers Gottlieb "the kind of man who carries civilization on his shoulders," adding that Gottlieb is "a pessimist who voices his doubts . . . of man's superiority to animals, yet his own genius advances progress and proves man's superiority."
Not a person to cater to public opinion or to his superiors in office, Gottlieb naturally makes enemies. His rift with Martin, caused by a trivial incident, lasts for several years. All the while, Gottlieb is changing positions. His home background is adequate but rather stark. Two of his three children are disappointing. He finally sinks into senility before Martin returns from St. Hubert and never comprehends the story of the phage. Sympathetic interpretation like that in the case of Gottlieb is rare in Sinclair Lewis, who is cynical toward most of his creations.