Martin is a 21-year-old sailor from the working class. He possesses a strong physical build scarred by years of manual labor and fighting. Despite his lack of formal education, he has a deep, instinctive drive for knowledge and a keen sensitivity to beauty. Meeting the bourgeois Morse family ignites his ambition to educate himself, leading him to pursue a career as a writer in hopes of proving himself worthy of the woman he loves.

Ruth is a 24-year-old college student studying English at the University of California. Raised in a sheltered, upper-class environment, she possesses a conventional view of art, education, and society. She takes an interest in tutoring Martin, acting as his guide to proper grammar and etiquette, but remains blind to the harsh realities of his working-class life.

Brissenden is an enigmatic, affluent intellectual and poet who suffers from tuberculosis. He holds strong socialist views and despises literary magazines, believing art should be created solely for the sake of beauty. He lives recklessly, seeking strange thrills to maximize his remaining time, and introduces Martin to bohemian circles in San Francisco.

Lizzie is a young, working-class woman whose hands bear the permanent scars of cannery labor. She possesses natural intelligence and quick wit but lacks formal education. She develops a deep, unpretentious affection for Martin, valuing him for his character rather than his potential for wealth or status.

Joe is a veteran laundryman who has spent 18 exhausting years toiling in hot, physically demanding resort laundries. He relies on weekend drinking to cope with the grueling, repetitive nature of his work. He dreams of a transient life free from unrelenting labor and views a past hospital stay as the only real rest he has ever experienced.

Maria is a hard-working Portuguese widow and immigrant who supports her children by washing clothes and selling milk from her two cows. Known in the neighborhood for her tough exterior and quick temper, she maintains a kind heart beneath the surface. She notices Martin's intense work ethic and physical hunger, often stepping in to help him.

Arthur is a young man from a wealthy Oakland family. After Martin rescues him from an assault by local hoodlums, Arthur invites the sailor to his home for dinner, inadvertently exposing Martin to the bourgeois lifestyle that alters his life's trajectory.

Norman is one of Ruth's brothers. He shares the same upper-class upbringing and bourgeois sensibilities as the rest of the Morse family, generally aligning with his parents' views on social propriety.

Mr. Morse is the patriarch of the Morse family and an established lawyer. He holds conservative, bourgeois values and views Martin's lack of formal employment with suspicion. He prefers young men of similar social standing and conventional career paths for his daughter.

Mrs. Morse is Ruth's mother, who carefully monitors her daughter's social interactions. She initially views Martin as a useful tool to awaken Ruth's interest in men but actively schemes to prevent any serious romantic attachment between them once the risk becomes apparent.

Gertrude is Martin's sister. Her spirit and physical health have been worn down by years of heavy domestic labor and a difficult marriage. She cares for Martin but fails to understand his literary ambitions, preferring simple stories with happy endings.

Bernard is Martin's brother-in-law, who runs the Higginbotham Cash Store. He is a penny-pinching, highly critical man who frequently belittles Martin's efforts and overworks his wife. He measures human value entirely by conventional labor and financial income.

Marian is Martin's younger sister. She shares the family's working-class pragmatism regarding employment. Her hands visibly reflect her background, bearing the scars of missing fingertips from a paper-box factory accident.

Hermann is a German bicycle mechanic engaged to Marian. He possesses rigid, conventional views on morality and labor, making him highly critical of Martin's writing pursuits. He views Martin's poetry as offensive and strongly disapproves of his lack of a traditional trade.

Will is an acquaintance of the Morse family who openly scoffs at Ruth's pursuit of culture for culture's sake. He possesses enough self-awareness to recognize that Martin's interest in education is entirely tied to his specific goal of becoming a writer.

Kreis is a former university professor who lost his position for challenging academic dogma. He hosts gatherings of bohemian intellectuals in his apartment, facilitating intense philosophical and political debates far outside mainstream bourgeois thought.

Caldwell is a young English professor from the University of California whom Ruth deeply admires. He engages in deep biological and philosophical conversations with Martin, openly conceding points when Martin critiques his arguments.

Judge Blount is a frequent guest at the Morse household who represents the political and intellectual establishment. He frequently clashes with Martin over politics, paternalistically diagnosing Martin's individualism as socialism.