When I was studying Art History, the most fascinating artists to me were the ones that made an effort to do something entirely different — the men and women that stuck their tongue out at the 'norm' and refused to make the highbrow art world happy.
The wacky Marcel Duchamp, a Parisian who moved to New York in 1915 to escape the war, was one of these artists.
Duchamp is most well known for his readymades — an object from popular or material culture presented as-is, without any further manipulation, as an artwork by an artist. He believed that art should appeal to the intellect and not the senses, and thought that presenting every day objects as art would do just that.
His most notorious (and hilarious) readymade was the Fountain (below) — literally a urinal that was turned 90 degrees and signed with the pseudonym "R. Mutt", a play on the manufacturer J.L. Mott Iron Works.
Duchamp submitted the work anonymously to the first annual exhibition of the American Society of Independent Artists in 1917 as a test to see how open the society was (ironically he was a founding member himself). Not surprisingly, the majority of the society's member's declared that the piece was NOT art and they refused to exhibit it in the show — Duchamp immediately resigned from the society.
Stieglitz's photo above is the ONLY known image of the original Fountain, as it mysteriously disappeared after it was rejected by the society in New York. Duchamp dealt with this loss by producing several more versions of the Fountain by simply buying new urinals and signing them "R. Mutt/1917" (one of the copies can be seen at SFMOMA — San Francisco Museum of Modern Art).
Whether you agree that it is 'art' or not, you have to admit that these works elicit a reaction, and I would think a reaction to their work — which usually leads to a conversation — is all that an artist could hope for...