Marcel Duchamp, Bicycle Wheel, 1913
 
Why is this art work included here? Duchamp wrote: “In 1913, I had the happy idea to fasten a bicycle wheel to a kitchen stool and watch it turn. To set the wheel turning was very soothing, very comforting, a sort of opening of avenues on other things than material life of every day. I liked the idea of having a bicycle wheel in my studio.” With these words he identifies exactly the fundamental difference between the play mode and the mode of ordinary life.