The terms 'realism' and 'naturalism' are, in the criticism of the nineteenth-century novel, often used as if they named the same project — the depiction of ordinary life with attention to the specifics of place, person, and material condition. The conflation is convenient but misleading. The two projects share an interest in the ordinary and a suspicion of the heroic, but they differ in their relation to the explanatory framework within which the ordinary is presented, and in what they ask the novel to do.
The realism associated, in the standard accounts, with figures like Eliot and James understands the novel as a study of moral and psychological complexity. Its characters are presented as agents whose choices, however constrained by circumstance, retain a moral weight that the narrative is interested in tracing. The conditions of life — class, money, the texture of work — matter to such novels, but as the medium within which moral choice operates rather than as the determining frame from which moral choice is to be deduced. The realist novel takes the social setting seriously without treating its characters as merely the products of that setting.
The naturalism associated, in the same accounts, with figures like Zola and Norris takes a step further. The novel becomes, on the naturalist view, something closer to a quasi-scientific investigation of how social and biological conditions determine outcomes. Characters retain a kind of agency, but the narrative is more interested in the forces that constrain that agency than in the choices the characters are making within the constraints. The shift in interest is small in description and large in consequence: the realist's moral attention to character becomes the naturalist's diagnostic attention to circumstance, and the novel becomes a different kind of artefact in the process.
To say this is not to elevate one project over the other; both have produced novels of permanent interest, and neither captures the whole field of nineteenth-century fiction across its many strands. It is to insist that the convenience of using one word for both flattens a distinction the novels themselves make plain to anyone who reads them carefully. The conscientious reader of Middlemarch is being asked, by the novel, to do different work from the conscientious reader of Germinal; to use the same critical term for both is to underprepare the reader for the difference the novels were written to articulate in their own terms.
The primary purpose of the passage is to: