Please elaborate --it sounds contradictory.
A theoretical presumption indeed remains that a majority of extant documents is more likely to represent a majority of ancestral documents at each stage of transmission than vice versa. (Brooke Foss Westcott and Fenton John Anthony Hort, The New Testament in the Original Greek, 2 vols. (London: Macmillan, 1881), 2:45.)
Hort claimed a total absence of "distinctively Byzantine" readings from manuscripts, versions, and Church Fathers before the mid-fourth century AD. Hort considered this argument to "prove" that readings found exclusively in later Byzantine manuscripts had no known early support and therefore absolutely could not have existed prior to AD 350. Hort was extremely adamant on this point.
However, over 150 "distinctively Byzantine" readings have been found in papyrus manuscripts predating AD 350, even though totally unattested by versions and Fathers. (Hort emphatically maintained that, were this principle overthrown, his entire hypothesis would have been demolished).
In view of the transmissional history suggested, the fallacy of the "older is necessarily better" argument should already have been made clear. Going beyond the contents of the earliest manuscripts, however, the editors would stress (following Burgon and many other critics) that it is not the age of the manuscript itself, but the quality and antiquity of the text it contains which is the real item of value.
Most early manuscripts in existence today have been affected by the uncontrolled nature of textual transmission which prevailed in their local areas, as well as by the persecutions which came continually against the church. The whole matter of early copying practices is hypothetical, regardless of which textual theory one prefers. We know nothing beyond what can be deduced from what survives. In the early papyri, we may have only personal copies, and not those which were generally used by the churches themselves. Also, the papyri all come from a single geographic area, and reflect a good deal of corruption, both accidental and deliberate. One should not summarily question the integrity of all early manuscripts because of the character of this limited sample from Egypt.
There is good reason to presume that most early copies -- many made directly from the autographs themselves -- would have been as accurate as ordinary care would humanly permit, especially for Holy Writ. Church sources in particular would not knowingly send forth what they would have considered "defective" copies. At least the first and second copying generations should have been generally secure. Responsible scribes would presumably take general care with their sacred deposits.
Although a healthy respect for the sacred text generally prevailed, keeping corruption to a minimum, even the orthodox sometimes took the opportunity to alter the text, under the supposition that they were "improving" or "restoring" the text with their corrections. Heretical tampering did occur, as witnessed by the work of Tatian and Marcion, but the church as a whole, and especially its leaders and theologians, were keen watchdogs against such deliberately-perverted manuscripts. It is not without significance that today we know of Marcion's heretical text only from citations in the Church Fathers, and the heretic Tatian's Diatessaron is seen in but one Greek manuscript fragment, despite its early widespread popularity even among the orthodox.
Yet, even though heretical alterations were not tolerated, nowhere in the early Fathers do we find any indication that in those early centuries a uniformity of text was a concern or demand. Had common scribal alteration been a concern, the Fathers would have spoken out as strongly as they did against the theology and text of the heretics. The evidence of the existing early manuscripts as well as the Patristic quotations of Scripture is plain in this regard. The manuscript text in the earliest centuries had been corrupted to a degree, chiefly through the agency of common orthodox Christians. The Fathers, like all other Christians, had to make do with the manuscripts currently available. They did not actively seek to "restore" the autograph form of that text; such was not their purpose.
The text found in the manuscripts of the second and third centuries, therefore, is in many cases corrupt, and to that extent somewhat removed from the autograph text. Not all manuscripts showed the same degree of corruption, however, as even the early papyri demonstrate. Only the continual process of manuscript comparison and cross-correction as practiced throughout the centuries would succeed in weeding out early scribal corruption and conflicting variant readings. The same process would later keep the vagaries of individual Byzantine-era scribes in check.
Dr. Maurice Robinson, Senior Professor of New Testament Greek, Southeastern Baptist Theological Seminary.
(In the interests of full disclosure I consider Dr. Robinson a friend and fellow laborer in the Vineyard of our Lord.)