This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Emile Zola did not want Le Roman experimental (1880) read as a metaphor. The physiologist Claude Bernard had argued, in his own 1865 Introduction to the Study of Experimental Medicine, that a scientist advances not by merely observing nature but by intervening, placing an organism under controlled conditions and watching what a specific variable produces. Zola's treatise proposed, at real length and with real seriousness, that the novelist could do the same thing to a fictional character: place a person of known heredity into a specific environment and let the plot serve as the controlled experiment, its outcome dictated by cause and effect rather than by authorial sentiment or moral convenience. The twenty novel Rougon-Macquart cycle, written across more than two decades, was Zola's attempt to run that experiment at the scale of an entire family across the Second Empire, tracing how alcoholism, ambition and circumstance moved through its branches. Critics at the time and since have questioned how literally scientific the method really was in practice, since a novelist choosing which variables to isolate is still making an artistic choice Bernard's laboratory did not require. But the ambition itself, to make the novel answerable to the same standard of evidence as a scientific report rather than to taste or moral instruction, is what gave literary Naturalism its name and its argument, and Zola never claimed to have merely described the method. He claimed to have founded it.