In “The Naturalism of Mr. Dreiser” (1915), the critic Stuart P. Sherman found nothing to praise in Theodore Dreiser's naturalism, which, Sherman complains, “drives home the great truth that man is essentially an animal” impelled by a “jungle-motive,” with protagonists that acquire not wisdom but “sensations.” Treating morality as an innate feature of human nature, Sherman singled out as unrealistic the idea that Dreiser's Jennie Gerhardt would feel not “sin or shame or regret” at bearing a child out of wedlock. He concludes that, unlike realism, which relies on a theory of human behavior, naturalism is “based upon a theory of animal behavior” and lacks the “moral value” and “memorable beauty” of true art. Naturalism had weathered similar charges of indecency, crudity, and a lack of decorum since its appearance on the American literary scene in the mid-1890s. Late nineteenth-century theories of Darwinian evolution had not only undercut the supposedly “natural” division between humans and animals but had also questioned the “natural” itself. Was morality “natural,” or love, or duty? Or were they all simply socially acceptable manifestations of human drives such as fear, desire, and self-preservation? Conservative critics like Sherman were understandably worried by the work of Dreiser and others like him, for American naturalism, in applying scientific principles to the medium of fiction, threatened to strip the conventional pieties from the façade of the social order.