Industry in art is a ...

Industry in art is a necessity - not a virtue - and any evidence of the same, in the production, is a blemish, not a quality; a proof, not of achievement, but of absolutely insufficient work, for work alone will efface the footsteps of work.
 James Whistler

Quotes from the same author

The explanation is quite simple. I wished to be near my mother.
 James Whistler
The masterpiece should appear as the flower to the painter - perfect in its bud as in its bloom - with no reason to explain its presence - no mission to fulfill - a joy to the artist, a delusion to the philanthropist - a puzzle to the botanist - an accident of sentiment and alliteration to the literary man.
 James Whistler
The rare few, who, early in life have rid themselves of the friendship of the many.
 James Whistler