Everybody knows that the terms and the distinction between them were introduced by Van Wyck Brooks, but what is not so widely appreciated is that he introduced them in the service of the Left. The “lyrical Left,” to be specific; America’s first Left, according to the historian John Patrick Diggins. Its intellectual spokesman was Randolph Bourne, creator of the American antiwar movement; its political leader, Eugene V. Debs. Brooks was an undependable Leftist for whom organized politics was secondary, although he pioneered the attitude that was summarized in the later Leftist slogan the Personal Is Political:
For Brooks, that middle was situated between highbrow and lowbrow culture, an antithesis (or what would now be called a binary opposition) that he saw as uniquely American:
But the middle culture, when it finally emerged, was not exactly what had been dreamed of by the lyrical Left. It was instead what Dwight Macdonald called a “middlebrow compromise,” a “peculiar hybrid” that resulted from mass culture’s “unnatural intercourse” with high culture:
But a large portion of “serious” contemporary fiction is also written out of the middlebrown compromise. Much of what passes for “genre-bending and stylistic play,” to adopt Michael Chabon’s phrase for it, is little more than the attempt to be simultaneously ordinary and refined. In Thomas Pynchon’s Inherent Vice, for example, a sensibility and technique that were once considered avant garde are placed in the service of the vaguely Leftist project of unmasking the system of the real relations which govern the existence of individuals:
How, then? Macdonald found promise in the very fragmentation of the literary marketplace to which I drew attention the other day. After the Second World War, he pointed out, it was discovered that
 Van Wyck Brooks, “Highbrow and Lowbrow,” Forum 53 (April 1915): 481–92.
 Dwight Macdonald, “Masscult and Midcult,” in Against the American Grain (New York: Random House, 1962), p. 37. Subsequent reference in parentheses.