Pinning the tail on Picasso's donkey. Is it still your art, if someone adapts it?

"It's like adding a tail onto an animal painted by Picasso. It's ridiculous"- Sir Anthony Caro

Last week ARTINFO reported that Sir Anthony Caro was caught up in an arguement with auction house bonhams over a sculpture of his, that had been modified by the purchaser but was being sold as his work. Disowning the work, he stated "It's a very bad thing for artists to know that the work can be destroyed or changed and that they have no recourse. They should be able to say: look, this is not my work." The argument is over some (imho awful) metal feet that have been welded onto the bottom of the sculpture. This raises some interesting questions in regards to the integrity of any work you create. If someone adapts your creations, when does the work cease to become your own? I am not talking about vandalism or deliberate destruction of the work, but where by the artists creation or idea has been developed by someone else. We might argue, in Caro's case, that these are just supports and the main body of the work is still intact, but to counter this view, surely the feed didn't need to be welded on and made a permanent feature. Interestingly enough if we look to the likes of artists such as Anthony Gormley and David Nash, who predominately make large scale public works, they seem to have a more relaxed view to the lifecycle of their work, in particular David Nash who's wooden sculptures are often not only shaped by human (for example eroded by being walked on), but also by nature.

Unfortunately this isn't a question with a black and white answer. On a case by case basis we may take a different stance.  Surely an artist should have the right to disown their work, if modified, and that they feel it misrepresents them. At the same time we should also respect the lifecycle of work we put into the public arena and appreciate the rewards of watching it evolve, with the knowledge that you were the catalyst that started the process.