Pablo Picasso and  Georges Braque’s collages opened the door for other artists to use real-life materials in their art. Marcel Duchamp—who first gained recognition exhibiting with the Cubists—took their technique one step further. He presented objects from the world as artworks on their own—without any addition of traditional mediums, i.e. as painting, sculpture, drawing or printmaking.

Duchamp’s decision to move in this direction was allegedly encouraged by a visit to the Salon de la Locomotion in Paris 1912, where he saw new modern marvels of technology and said to the sculptor Constantin Brancusi, “Painting is finished. Who can do better than the propeller?” From this moment, Duchamp (echoing the ideas of Paul Cézanne) criticized painting as a “retinal art” and sought to make more cerebral works, in which the ideas involved were just as important as the objects. Duchamp’s readymades were the result.

The readymades are among the most important works of art of the 20th century. They—even more blatantly than Picasso and Braque’s works—gave permission for anything to be a work of art; and provided the impetus for Dada—which looked at Duchamp as their “patron saint”—as well as so many of the major movements of the 20th century, such as Neo Dada, Pop Art, and Conceptual Art. For many artists, critics, curators and historians, it has become clear that Duchamp (as opposed to Picasso or Andy Warhol) is the most important 20th century artist.

Duchamp’s first true readymade was his Bottle-Rack, which he made in 1914. It’s just that—a galvanized iron rack made for drying bottles on and Duchamp called it a “readymade” because he thought of it as a readymade work of art. He did sign it though (as an artist would their painting). The “art” of this work accordingly became Duchamp’s selection of it, which, in the words of André Breton, the founder of Surrealism, “promote[d] it to the dignity of objects of art.” Such a definition of art was an entire paradigm shift. This work could not be understood as a traditional medium, there was basically no “hand” of the artist present, and the work was made in a factory. It was thought of as anti-art, the most extreme rejection one could make in the history of art. In many respects, it remained the most extreme statement in art history until the birth of Conceptual Art, which was founded on the general idea that the idea for the work was most important, to the extent that you didn’t even need an object to have a work of art.

Duchamp’s first attempts at making readymades began two years before his Bottle-Rack with his Bicycle Wheel of 1913, which is basically a bicycle wheel (with no tire on it) that turns if spun and is mounted upside-down into a draughtsman’s stool. Art historians characteristically refer to the Wheel as an “assisted readymade” because, unlike the Bottle-Rack, it necessitated some assistance by the artist to make it. In other words, Duchamp needed to stick a bicycle wheel in a chair upside-down to create the work. Also, according to Duchamp, the Bicycle Wheel was not a true readymade because it could be interacted with, i.e. the wheel could be spun. Because of this, it’s been argued that Bicycle Wheel was the first example of kinetic sculpture.

In subsequent years, while Duchamp created other readymades, such as In Advance of a Broken Arm (a snow shovel) and Traveler’s Folding Item (a typewriter cover), his most significant was one he and Joseph Stella sent in anonymously to the hanging committee of the 1917 exhibition organized by the Society of Independent Artists at the Grand Palace, New York (of which Duchamp was a founding member). This work was the notorious Fountain, a porcelain urinal turned upside down and signed R. Mutt. (R supposedly could stand for Richard (which meant “moneybags” in German) and Mutt for the J.L. Mott iron works where Duchamp bought the urinal; Mutt could also be a play on the comic, Mutt and Jeff.)

When faced with Fountain, the hanging committee at the Society of Independent Artists refused to exhibit it—although it had pledged to show any work by an artist who paid the $6 fee. As a result a small controversy developed. Duchamp removed his works from the exhibition in protest—though again no one knew it was Duchamp who was R. Mutt. He also published an article in The Blind Man, a small magazine that he edited himself. In the article, he explained, “Whether Mr. Mutt with his own hands made the fountain or not has no importance. He CHOSE it. He took an ordinary article of life, placed it so that its useful significance disappeared under the new title and point of view and created a new thought for that object.” As for the objections to the work’s appearance, Duchamp pointed out that similar fixtures were seen every day in plumbers’ show windows and added succinctly, “the only works of art America has given are her plumbing and her bridges.”