The paleontologist Robert Broom developed an image of himself as a scientific rebel, assailing the centers of expert authority from the margins as he pursued a career whose idiosyncratic path was dictated less by the promise of professional security or material reward than by the whims of his curiosity and the desire to be free of institutional constraint. In the 1930s Broom put forward an idiosyncratic evolutionary theory that rejected both Lamarckian and Darwinian mechanisms in favor of "spiritual agencies" responsible for the evolutionary process. He characterized his views as a dissent from the orthodox evolutionary thought of most scientific authorities, and he believed such acts of dissent to be integral to the virtuous conduct of science. Broom was drawing on a familiar trope in the history of the sciences--that of the scientist as a heroic rebel. However, the religious inflection of Broom's theory, and his characterization of fellow scientists as purveyors of orthodoxy, reverses the more common form of the trope, which associates religion with orthodoxy and institutional authority.