marcel duchamp
Étant donnés
dedomena
The French expression étant donnés corresponds to the data (Latin) or dedomena (Greek) in Euclid. They are the necessary givens for showing a geometrical proof.
Marcel Duchamp (1887-1968) worked secretly on Étant donnés 1° la chute d'eau / 2° le gas d'éclairage (Given: 1° The Waterfall / 2° The Illuminating Gas) for twenty years (1946-1966). It was, according to his wish, installed posthumously in Philadelphia Museum of Art in 1969. Duchamp also wrote a manual in French with handwritten instructions and photographs on how to install it. The manual was published in facsimile in 1987 by the museum.
Étant donnés can only be seen through two peeping holes in an old wooden door placed in a small room near the other works by Duchamp at the museum.