There is a gap between the original writing down (the autograph) of each of the various documents that were later incorporated into the New Testament and even the oldest surviving manuscript copies of the New Testament form of any such document. Philip Wesley Comfort says: "The time gap between the autograph and the extant copies is quite close − no more than one hundred years for most of the books of the New Testament. Thus we are in a good position to recover most of the original wording of the Greek New Testament.". Scholars assume the general reliability of the texts of ancient authors attested by extremely few manuscripts written perhaps a thouosand years after their death: the New Testament is much better attested both in quantity and in antiquity of manuscripts. On the other hand, Helmut Koester says that the discovered papyri tell us nothing of the history of a text in the 100 to 150 years between when the original autograph was written and when its New Testament form was canonized. In line with the common view, Koester places canonization of the New Testament at the end of the second century. David Trobisch proposes a shorter interval, saying that a specific collection of Christian writings closely approximating the modern New Testament canon was edited and published before 180, probably by Polycarp (69–155).