Dörpfeld, it is well known, refuses to accept this conclusion. But his method of dealing with the testimony of Vitruvius has changed since he wrote his book on the Greek theatre. He then supposed that Vitruvius had been guilty of an error. While admitting that he was correct in his measurements of the Greek proscenium, he asserted that he had made a mistake as to its purpose; that he had confused the background of the Hellenistic theatre with the stage of the Roman.[462] But this explanation is one which it is impossible to accept. It is absurd to suppose that Vitruvius was mistaken. He was a professional architect, writing about his own special subject, and writing at the very time when many of these Greek proscenia were being erected. His remark about the Greek stage is not introduced as an _obiter dictum_, but is made the basis of the distinction which he draws between Greek and Roman theatres. He had evidently therefore thought about the subject. But even if we suppose that he could make a mistake of this kind, even if we suppose that he had never been in Greece, and never seen a Greek play acted there, still it is incredible that such an absurd error should have remained uncorrected in his book. The connexion between Greece and Rome was so intimate, that there must have been thousands of people in Rome who had seen Greek plays performed in a Greek theatre, and knew how it was done. If Vitruvius had made this absurd blunder, some one would have been sure to point it out to him, and he would have had it corrected.