The type of borrowing today called appropriation began with the readymades of Marcel Duchamp (1887-1968). After directly witnessing the carnage of war, Duchamp felt that art was frivolous in comparison and created a number of appropriated works he presented as examples of "anti-art" or an "anti-aesthetics." He and other artists who were part of the short-lived Dada movement believed that the random accident held more weight than the studied perfection of academic art, and that an artist's conceptual repurposing of an existing object was a valid form of creation. Duchamp conceived of several terms for his art. The readymade is an object repurposed by the artist without manipulation; for example, Duchamp's Bottlerack is a rack used to dry bottles; Duchamp merely placed that object into a different context. A readymade-aided work, however, has been manipulated by the artist in some way. In Bicycle Wheel and Stool two objects are combined so that neither can function as originally designed. This work not only pioneered kinetic sculpture (sculpture that moves), it also extended and reversed the idea of "art for art's sake"—the claim that art did not need to serve a specific purpose or educate its public, it could simply "be." By extension, the lack of function (in the wheel and the stool) could indicate the presence of art. Duchamp further played with the idea of function versus art in a third type that he identified only in theory—the reciprocal readymade—a Rembrandt painting used as an ironing board.
In the 1950s and 1960s, Duchamp's significance was rewritten as a younger generation of artists, notably Neo-Dadaists Robert Rauschenberg and Jasper Johns, began to use the found object not as "anti-art," but rather to prove that anything could be art if the artist said it was. Today both interpretations of Duchamp's contribution to the history of art have an influence on appropriation art. While the scholarship on Duchamp's contribution is vast, a few texts specifically address his role in shifting the perception of the copy from a mechanical process to a conceptual act. It is not surprising that these texts take a deeply theoretically approach to the subject. Stephen Bury in Artists' Multiples, 1935-2000 uses as his theoretical foundation Walter Benjamin's 1936 essay "The Work of Art in the Age of Mechanical Reproduction," having recognized the fact that Benjamin was writing just after Duchamp published an unsigned edition of his Rotoreliefs. While multiples appeared earlier, Bury is most interested in linking Duchamp's readymades and language jokes to trends in the 1960s—Pop Art, Fluxus (a performative revival of Dada soirées), Joseph Beuys's felt pieces, minimalist serial works, conceptual works with serial elements, and contemporary works by Jeff Koons, Damian Hirst, Tracy Emin, Jake and Dinos Chapman, and dozens of others.
Rosalind Krauss and Thomas Tucker approach Duchamp through the lens of philosopher Jacques Derrida. Krauss, in The Originality of the Avant-Garde and Other Modernist Myths, deconstructs the myth of originality. She shows how the avant-garde formed itself on sense of repetition, which Krauss connects to the use of the grid by 1960s minimalists. Krauss interprets Duchamp's and Warhol's appropriations differently than those of Jeff Koons, whom she terms a plagiarist. Tucker, in Derridada: Duchamp as a Readymade Construction, interweaves the work of Jacques Derrida and Duchamp to reveal the artist as deconstructionist. Derrida's concepts of deconstruction are applied to Duchamp's works The Large Glass and Bicycle Wheel and Stool, and his concept of différence is applied to Duchamp's works that included verbal puns as well as his adoption of a feminine alter ego named Rrose Sélavy (pronounced Eros, c'est la vie). Most of the essays and interviews in Martha Buskirk and Mignon Nixon's The Duchamp Effect were originally published in October, widely appreciated as an important venue for theoretically driven scholarship. The introduction by Hal Foster discusses the influence of Duchamp and the theoretical landscape against which it developed (Michel Foucault, Louis Althusser, Ferdinand de Saussure, and Jacques Lacan). Several essays and interviews with contemporary artists (e.g., Claes Oldenburg, Andy Warhol, Robert Morris, Ed Ruscha, Bruce Conner, Sherrie Levine, Louise Lawler, and Fred Wilson) allude specifically to Duchamp's influence, connecting his readymades to conceptual art and their contemporary practice. Artists' statements about the importance of Duchamp to their work is also the foundation of the exhibition catalogue Aftershock: The Legacy of the Readymade in Post-war and Contemporary American Art, which supplements two essays about the influence of Duchamp on contemporary artists with another compilation of artists' statements about his importance to their work, including Allan Kaprow, Joseph Kosuth, Robert Smithson, Joseph Cornell, Louise Lawler, John Baldessari, Robert Rauschenberg, Jeff Koons, and many others.