It would be most wholesome if for at least twenty years art historians were forbidden to refer to any derivations. If they were not allowed to account for a work of art mainly by tracing where it comes from, they would have to deal with it in and by itself--which is what they are most needed for.

Parables of Sun Light: Observations on Psychology, the Arts, and the Rest (ed. Univ of California Press, 1990) - ISBN: 9780520909052