A picture is a thing which ...

A picture is a thing which requires as much knavery, as much malice, and as much vice as the perpetration of a crime. Make it untrue and add an accent of truth.
 Edgar Degas

Quotes from the same author

What a delightful thing is the conversation of specialists! One understands absolutely nothing and it's charming.
 Edgar Degas
The artist does not draw what he sees, but what he must make others see. Only when he no longer knows what he is doing does the painter do good things. A picture is first of all a product of the imagination of the artist; it must never be a copy. If then two or three natural accents can be added, obviously no harm is done. The air we see in the paintings of the old masters is never the air we breathe.
 Edgar Degas
Art critic! Is that a profession? When I think we are stupid enough, we painters, to solicit those people's compliments and to put ourselves into their hands! What shame! Should we even accept that they talk about our work?
 Edgar Degas
One must do the same subject over again ten times, a hundred times. In art nothing must resemble an accident, not even movement.
 Edgar Degas
People call me the painter of dancers, but I really wish to capture movement itself.
 Edgar Degas