All study of Ovid ultimately is based on our imperfect knowledge of what he actually wrote. That knowledge depends almost entirely on some hundreds of manuscripts preserved in a multitude of libraries, situated for the most part in Western Europe. The versions of the text that they give all differ to a greater or lesser degree, and scholars must try to divine the errors that obscure the truth. In places where the manuscripts disagree none of them may be right, and even where they are unanimous there is no guarantee that what they show is what Ovid wrote.