The commanding art critic Clement Greenberg laid out the necessity of the art world’s modernist project in his now-canonical 1939 essay “Avant-Garde and Kitsch.” Forward-thinking art, he insisted, combats the docile complacency of a general public that is easily manipulated by consumerist forces and fascist regimes, who propagandize campy, mass-produced imagery

The growing Nazi threat in Europe added special urgency to the Jewish-American critic’s writing, but Greenberg’s essay, while influential, had perhaps unintended consequences. In it, he defined an unbridgeable line between the avant-garde and popular forms of art considered outside the official art world. The stark moral distinction between the two was clear: the former fights fascism, the latter propels it. Such high-minded divisions between so-called “high” and “low” art have been maintained by institutional gatekeepers for centuries, but if the art world is to become a more inclusive place for heterogeneous voices and styles, we must reevaluate the self-imposed boundaries it operates under.

In their new book Aesthetics of the Margins / The Margins of Aesthetics: Wild Art Explained, co-authors David Carrier and Joachim Pissarro trace a history of the institutionalization of taste, rejecting the binary of “serious” art shown in galleries and museums and what they call “wild” art, a wide range of creative enterprises—from street art to fashion to tattoos—that exist in a multiplicity of art worlds operating outside the system. It’s crucial to recognize that the hierarchical division of art forms—traditionally prioritizing oil painting and sculpture over textile arts and other “domestic” crafts—has abetted the exclusion of women, people of color, and artisans of the lower classes.

The first step to erasing these boundaries, Carrier told Artsy, is to recognize that the differences between them are, in fact, largely arbitrary, borne of any system’s need to police its borders. Carrier cited a literal example of the divide: “When you go to MoMA or the Met,” he said, “you see all of these people right outside the doors of the museums selling street art, paintings, and so forth. They’re so close, yet so far; they’re never going to be admitted into the art world.”

Thomas Kinkade Impressionist In our postmodern age, there might not be easily definable criteria for what constitutes high art versus kitsch, but Carrier cites irony as a major determining factor., he offered, was “fabulously successful; his paintings were in 1 in every 20 American homes.” Yet he was never taken seriously by the establishment. Carrier senses that this rejection was “because he was not ironical. He didscenes that have a sweet view of the world. That’s not accepted in the art world.”

Institutions have, little by little, become more accepting of various art forms over the last few decades. Major exhibitions of fashion and street art—like the Met’s “Heavenly Bodies,” which shattered the museum’s attendance record last year—have drawn thousands of visitors, along with the snooty disdain of some critics. But Carrier is still hopeful. “Anything can make its way [into the art world],” he posited, “but you can’t have everything coming in at once.”

It seems inevitable that major museums will only continue to expand their programming of commercially appealing exhibitions on “wild art” topics like popular music, street fashion, video games, or graffiti. Now is as fine a time as any for university art history programs to similarly seek out ways to take these subjects seriously, and incorporate them into their own curricula. While there are some interdisciplinary programs like this already in existence—mostly under the guises of “Cultural” or “Visual Studies,” the latter offered by the Eugene Lang College of Liberal Arts—more traditional art history courses could easily adopt this same spirit.

Still, as individuals, we can reap the simple but profound benefits of such openness to aesthetic experience. Researching the book with Pissarro, Carrier said, “opened our eyes to see lots of things that maybe we wouldn’t have looked at otherwise. That’s what we’re advocating. Open your eyes. There’s a lot to look at.”