Marcel Duchamps Urinal (or Fountain) of 1917 epitomized the question what is art?
In December 2004, Duchamps Fountain was voted the most influential artwork of the 20th century by 500 selected British art world professionals. The Independent noted in a February 2008 article that with this single work, Duchamp invented conceptual art and severed forever the traditional link between the artists labour and the merit of the work.
Jerry Saltz wrote in The Village Voice in 2006:
Duchamp adamantly asserted that he wanted to de-deify the artist. The readymades provide a way around inflexible either-or aesthetic propositions. They represent a Copernican shift in art. Fountain is whats called an acheropoietoi, [sic] an image not shaped by the hands of an artist. Fountain brings us into contact with an original that is still an original but that also exists in an altered philosophical and metaphysical state. It is a manifestation of the Kantian sublime: A work of art that transcends a form but that is also intelligible, an object that strikes down an idea while allowing it to spring up stronger.
The prices for replicas, editions, or works that have some ephemeral trace of Duchamp reached its peak with the purchase of one of the 1964 replicas of Fountain from the 1964 edition of eight, for $1.7 million at Sothebys in November 1999.
(source: Saltz, Jerry (2006-02-21). Idol Thoughts: The glory of Fountain, Marcel Duchamps ground-breaking moneybags piss pot. The Village Voice. https://www.villagevoice.com/art/0609,200859,200859,13.html )