Possible reality [is obtained] by slightly bending physical and chemical laws. - Marcel Duchamp

What I have in mind is that art may be bad, good, or indifferent, but, whatever adjective is used, we must call it art, and bad art is art in the same way that a bad emotion is still an emotion.

You [ Katherine Sophie Dreier; director of the Art Center in New York City; she co-founded with Duchamp and Man Ray the 'Sociéte Anonyme' in Manhattan in 1920] must understand:
My attitude toward the book is based upon my attitude towards 'Art' since 1918 – so I am furious myself that you will accept only partly that attitude [in a new publication by Katherine Dreier]. It can be no more question of my life as an artist’s life: [because] I gave it up ten years ago; this period is long enough to prove that my intention to remain outside of any art manifestation is permanent.. .The third question is that I want to be alone as much as possible.
This abrupt way to speak of my 'hardening process' is not meant to be mean, but is the result of '42 years of age'.. ..10 000 apologies for this rough letter and affectueusement
Dee -

He [= Duchamp himself, writing in the third person] 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 – created a new thought for that object.