In 1915, Mary Austin (1868-1934) wrote to her old friend and fellow writer Jack London (1876-1916) to upbraid him for failing to write a novel that truthfully depicted the life of a modern woman, and by extension, companionate marriage. Companionate marriage was a rational system based in idealism, tailor-made for the Progressive Era and for revolutionists such as Austin and London in Greenwich Village, who shared their era’s enthusiasm for scientific systems. Austin and London protested conventional forms of marriage both from the sociological standpoint of its unnecessary conventions and from its failure to account for the irrationality of sexual desire and its dampening effect on genius. Yet their accounts of unconventional unions reveal another set of problems. Pitting conventional marriage against its more revolutionary counterparts, Austin, in A Woman of Genius and Number 26 Jayne Street, and London, in “Planchette” (1908) and Little Lady of the Big House (1916), critique conventional marriage but also cast a cold eye on its Bohemian alternatives, revealing the gap between the ideal and the real in progressive marriage by highlighting the stubborn realities of gender inequality and of the irrational desire, cast in London’s “Planchette” as the supernatural world, that plagued their idealistic efforts.