To venture an answer to the question my title poses is to reveal something fundamental about how one understands and values literary form. As a result, any answer is far from a simple one: it depends on whom you ask, and, for that matter, on when you ask. Only a few decades ago, critics would likely have responded in the negative. Modernism, long associated with the experimental aesthetics of James Joyce, Virginia Woolf, Ezra Pound, and T.S. Eliot, was considered a proudly avant-garde phenomenon with little patience for the bestsellers, genre fictions, and other popular texts so prominent in the literary marketplace of the early twentieth century. Critics of crime fiction might well have said the same thing, arguing that the careful formulae of Golden Age mysteries and the hard-boiled naturalism of the detective fiction pulps seemed deliberately antithetical to modernism’s rarified, allusive energy. Today, though, critics of modernism and crime fiction are far more open to the affinities that unite their objects of study. Of course, those connections were there all along—Eliot and Gertrude Stein were well-known devotees of detective fiction, and Stein even made an effort at the genre with her curious crime novel Blood on the Dining-Room Floor—but with the growing awareness that “modernism” signifies a global effort at aesthetic innovation that blurs the boundaries between experiment and convention, coupled with the corresponding attention to genre fiction as a vital influence on multiple literary forms, contemporary critics are much more likely to say that crime fiction can indeed be modernist if we take modernism to be a set of formal, social, and theoretical preoccupations regarding what it means to live, and to create art, within a world we can describe as modern. Take, for instance, Whose Body?, the first of Dorothy L. Sayers’s Lord Peter Wimsey mysteries, published at the height of modernism’s influence in 1923. That novel introduced Sayers’s eccentric, damaged, and altogether striking protagonist, an amateur detective traumatized by his experiences in the trenches of the Great War. Sayers’s emphasis on Wimsey’s mind—his flashbacks to the horrors of the front as well as his processes of deduction, which, in Whose Body?, culminate in a flash of insight whose epiphany deliberately contrasts with the cool reasoning of a figure like Sherlock Holmes—marks her novel as a study in consciousness not unlike those of her modernist contemporaries. At issue is the essential question of how a detective thinks in order to identify a criminal, and how that thinking can or cannot be represented in fiction. Clearly, this is detective fiction with palpable modernist roots. Why, then, should we pose a question whose answer now seems obvious? If crime fiction of the early twentieth century clearly responds to and resembles those avant-garde novels with which it would have shared shelf space, what’s at stake in drawing attention to that fact? My own answer is that, while stereotypes regarding modernism as elitist and genre fiction as simplistic have largely been dismantled in critical circles, they still rear their heads in popular discourse. The immense appeal of J.K. Rowling’s Harry Potter series has led to fierce arguments regarding the appropriateness of YA literature—an enormous facet of the contemporary publishing landscape—for adult readers, while Anna Burns’s Booker Prize victory for her novel Milkman set off a debate over whether literary prizes should reward accessibility over experiment. What these arguments reveal is the stubborn persistence of hierarchical models of literary production, the belief that adjectives like “highbrow” or “lowbrow” signify anything beyond a set of assumptions about what “counts” as literature, and severely limited criteria for who makes that decision. Perceiving crime fiction and modernism as related—for modernism borrows just as much from popular genre fiction as genre fiction does from modernism—thus means seeing the literature of the early twentieth century as intimately connected in form and content in ways that traverse conventional boundaries between popular and experimental fiction. It illustrates the fact that we now value literature differently, recognizing the significance of generic categories without seeing them as autonomous or restricting our conception of what art can be.