If the Copy Is an Artwork, Then What's The Original?

Where is the line between appropriation and copy? Richard prince dances around this line with his work, creating dynamic visuals with borrowed imagery. What strikes me most about Richard Prince is the way he assembles his images. The appropriated image is scaled and distorted. Does this act of alteration create something new? As the author described in the article, Jim Krantz was the original photographer of the Marlboro shoot. His reaction to seeing his image at the Guggenheim was one of surprise, which eventually turned to anger as the success of Prince's pieces rose. I feel Krantz has a right to be annoyed at someone else gaining fame and fortune through one of his own images. Prince uses advertisements to create art and commentary, that is his medium. It is true that someone else had to create said advertisement, but one must presume they were compensated at the time of creation and these images could therefore be considered public domain. The last line of the article was very thought provoking, where Krantz asked if italicizing Moby Dick makes the book his, which it doesn't. I do see a difference however in Prince's alteration and re-contextualizing of predisposed images versus Krantz's example of appropriating a best-selling book.