John Ford examined the doctor's roles in society in three films: Arrowsmith, Doctor Bull, and The Prisoner of Shark Island. Of the three, Arrowsmith was the most prestigious production, nominated for four Oscars Awards, including Best Picture.
The film's prestige also stemmed from its literary source: it was based on the 1925 novel by Sinclair Lewis, who won the 1930 Nobel Prize for it, and was scripted by Sidney Howard, a Pulitzer-Prize winner for drama. Significantly, Lewis refused the 1926 Pulitzer in literature because of the prize's alleged advocacy of novels that represented “the wholesome atmosphere of American life and the highest standard of American manners and manhood.”
The film begins in a typical and favorite Ford manner, announcing that this is “the story of a man who dedicated his life to science and his heart to the love of one woman.” There is a good deal of irony in the title, for the film is about a man who struggles, but fails, on both fronts, in his dedication to pure science and in his role as a husband. Martin Arrowsmith (Ronald Colman) takes after his grandmother Emmy, a woman of “pioneer and stubborn stock.” In the first scene, she is seen in the prairie, holding the reins and refusing to go to Cincinnati, where her uncle lives. “We're goin' West! she tells her husband authoritatively, “They's a whole lot of new things I aim to be seeing yet!”
The scene switches to Elk Mills and Arrowsmith, aged 16, told by Doc Vickerson, a drunkenly country doctor (also a hunter and a naturalist), that he is going to make “a real scientist” out of him, “make you wanta find out things for yourself!” Doc Vickerson doesn't want Arrowsmith to follow him, “a poor old sawbone and drunk.” Indeed, the enthusiastic man attends Winnemac College, determined “not to be just an ordinary doctor.” I'm not interested in just giving people pills. I'd rather find the cure for cancer.” His mentor, Dr. Max Gottlieb (A. E. Anson), reaffirms his zealous ambition, “To be a scientist is born in a man, and in very few men.”
But Arrowsmith gives up a great career as a research scientist to be a country doctor. He settles down with his loyal wife Leora Tozer (Helen Hayes) in Wheatsylvania, South Dakota, a town of 366 inhabitants. “Real man's country!” Frontier! Opportunity!” declares Arrowsmith with excitement. Though proud of being a country doctor,” it's Leora who tells him what his duties are: “You gotta make the young folks get married when they ought to, and stay married when they don't want to. You gotta lecture the big boys on the evils of drink and do your own drinking with the shades pulled down! You gotta see that the milk's pure and the meat's fresh and the backyards are kept tidy.”
When his first patient, a little girl, dies, he blames himself, “I was a rotten doctor.” Eager to concoct a serum that will save the cattle from dying of the Blackleg, his efforts are resented by the city bureaucrat, the state veterinarian. “Saving cows may not be saving mankind,” says Arrowsmith, “but it's a step in the right direction.” Discrediting the veterinarian, he sends his discovery and report to Washington.
The dilemma faced by Arrowsmith is devoting himself to a humanistic, people-oriented, medicine, or to research-oriented science. At first, he gives up his practice in the small-town and moves to New York City, to work as a medical researcher, a more prestigious if less paying position. His sponsor, the brilliant Gottlieb, in a stereotypical role of a Jewish scientist, predicts bright future for him as a scientist.
But after two years, he gets depressed, realizing “I haven't accomplished a darn thing.” “I'm no good,” he tells Leora, “I'm worse at science than I was a doctoring.” He thus devotes his life to the combat of the bubonic plague in the West Indies. Gottlieb advises him to conduct an experiment: to give the experimental serum to half of the population, the other half serving as a control group.
When the white inhabitants refuse the serum, Arrowsmith offers it to the black people. “It will be a privilege for my people to have saved the world,” declares Marchand, the black doctor. But administering his serum to the entire population ruins his chance of conducting a scientific experiment. “I betrayed you,” says Arrowsmith to Gottlieb at the end, “I didn't add to knowledge. I did the humane thing. I lost sight of science.”
In the city, Arrowsmith courts Joyce Lanyon (Myrna Loy); he considers, but is not engaged in, an affair with her. However, spending time with Joyce precludes him from returning home in time to save his wife. He pays a high price: neglected, his wife dies alone of the same epidemic he will later cure.
Arrowsmith is not completely devoid of vanity. “I'm off to glory,” he tells his wife before departing for the tropical island, “If I pull this off I'll be a great man!” This is what makes the next scene, in which Leora dies in pain alone, on the floor, so powerful. Guilt-ridden, he returns to the city but renounces both pure science (“To hell with science”) and Joyce. In an ambiguous, fantasy-like, closure, Arrowsmith believes he is reunited with his dead wife.
The film contains “message” speeches about idealism and integrity that are the staple and hallmark of many Depression films. Ford stresses the values of self-sacrifice, dedication to the cause, nobility of character, and the importance of standing above petit quarrels. For instance, in the West Indies, Arrowsmith lectures about his concern “for all continents and generations,” though his speech is more appreciated by the black doctor than the white administration.