Banksy, in an interview with AJ Schnack:
I’ve learnt from experience that a painting isn’t finished when you put down your brush – that’s when it starts. The public reaction is what supplies meaning and value.
Seth Godin, on his blog:
Art is what we call…the thing an artist does. […] Art is not in the eye of the beholder. It’s in the soul of the artist.
(More thoughts here: Art and influences)