Reexamining Flaubert's use of simile in Madame Bovary yields fresh insights into old, deep questions in the study of realism: depiction of thought, free indirect speech, the relationship between representation and reality. Barthes thought the content of a simile was ultimately merely a gesture toward the realness that it thereby signified, and Proust assumed a simile ought to be precise, singular, and novel—but Flaubert's similes actually interact with his famously ironic narration to depict a particular kind of thought and feeling on the part of his characters. They are negative similes, hollow, meant to refract the comparison backward: as much as X is like Y, X is not Y. These similes intensify and dignify what they describe, but only within the penumbra of Flaubert's characteristically ironic detachment. By setting what is the case side by side with what is not, they continually aerate the prose with a sense of the grandeur that reality fails to attain. They challenge the reader to look at simile as an ironic figure rather than as needless ornament or (pace Barthes) straightforward denotation. The ambiguous relationship of simile to reality in Madame Bovary makes it a fitting rhetorical figure through which to consider the novel itself.