I'd like to direct your attention to another piece in the New York Times by Errol Morris. This is on art forgery, and promises to be the first in a seven-part series.
From the article: "what makes a work of art great? Is it the signature of (or attribution to) an acknowledged master? Is it just a name? Or is it a name implying a provenance? With a photograph we may be interested in the photographer but also in what the photograph is of. With a painting this is often turned around, we may be interested in what the painting is of, but we are primarily interested in the question: who made it? Who held a brush to canvas and painted it?"