Are the Oldest Manuscripts the Best?
Answered by Wilbur Pickering
What follows has been copied from my book, The Identity of the New Testament Text (first published in 1977), with some additions. Anyone wishing to check the references should consult that book.
Burgon recognized the “antecedent probability” with these words:
The more ancient testimony is probably the better testimony. That it is not by any means always so is a familiar fact. . . . But it remains true, notwithstanding, that until evidence has been produced to the contrary in any particular instance, the more ancient of two witnesses may reasonably be presumed to be the better informed witness. 
This a priori expectation seems to have been elevated to a virtual certainty in the minds of many textual critics of the 19th century. The basic ingredient in the work of men like Tregelles, Tischendorf and Hort was a deference to the oldest MSS, and in this they followed Lachmann.
The ‘best’ attestation, so Lachmann maintained, is given by the oldest witnesses. Taking his stand rigorously with the oldest, and disregarding the whole of the recent evidence, he drew the consequences of Bengel’s observations. The material which Lachmann used could with advantage have been increased; but the principle that the text of the New Testament, like that of every other critical edition, must throughout be based upon the best available evidence, was once and for all established by him. 
Note that Zuntz here clearly equates ‘oldest’ with ‘best’. He evidently exemplifies what Oliver has called “the growing belief that the oldest manuscripts contain the most nearly original text.” Oliver proceeds:
Some recent critics have returned to the earlier pattern of Tischendorf and Westcott and Hort: to seek for the original text in the oldest MSS. Critics earlier in the 20th century were highly critical of this 19th century practice. The return has been motivated largely by the discovery of papyri which are separated from the autographs by less than two centuries. 
But, the “contrary evidence” is in hand…
1. Burgon, The Traditional Text, p. 40. I disagree. Great age in a manuscript should arouse our suspicion: how could it have survived for over 1,500 years? Why wasn’t it used and worn out?
2. Zuntz, The Text, pp. 6-7.
3. Oliver, pp. 312-13.