Is There Evidence of a “Clean Transmission” from P75 to Codex Vaticanus?

Author’s note: In the first draft of the article, I was responding to the claim that P66 and P75 had a clean transmission to Vaticanus. Dr. Boyce informed me that he was making the claim only about P75. The article has been edited to reflect this correction.


In a recent YouTube debate between Dr. Jeff Riddle and Dr. Stephen Boyce, the claim was made that P75 has a clean transmission up to Vaticanus, spanning the “150 year gap” between the two. This occurs around the 24 minute mark in the video which can be found here. In this article I want to present my reader with information regarding this particular claim. In order to frame this discussion, it is important to discuss what it means for a manuscript to have a “clean transmission” to another manuscript. This isn’t defined at all in the debate, but this is a critical component of Dr. Boyce’s presentation. 

A Clean Transmission

The problem with this claim is first that Dr. Boyce does not define what he means for a manuscript to have a clean transmission. Scholars have defined varying levels of agreement between manuscripts, however. A metric used by textual scholars called pregeneological coherence is likely the closest thing we can look at to determine whether or not two manuscripts share a clean transmission from one to the other. This seems to be the best metric that can be used, so I’ll take pregeneological coherence as my baseline for the analysis within this article. Prior to presenting these numbers, it may be valuable for my reader to understand what this metric is actually describing. Pregeneological coherence is defined by Dr. Peter Gurry and Dr. Tommy Wasserman as, 

“The number of shared readings between any two texts constitutes their pregenealogical coherence. This is expressed as a percentage of the number of places where the two witnesses are comparable.”

Gurry & Wasserman, A New Approach to New Testament Textual Criticism, 137

According to Gurry & Wasserman, 78% pregenealogical coherence serves as a sort of baseline, or cut off point in determining whether or not two manuscripts should even be considered as relatives to one another(45). Using this as a basis for my analysis, If two manuscripts have less than 78% coherence, it is very likely that they are not directly related. While this is not an absolute science or definitive, it does give us a lot of information when determining if there is a clean transmission between two manuscripts. Now the challenging component of this discussion is determining where the threshold is for what can be considered a “clean transmission.” Do we say that 85% qualifies as clean, or should we expect closer to 95%? If a scribe generally copies accurately, is a 22% difference evidence of a “clean transmission,” or does it tell us that there is likely another manuscript used that can account for the difference? A new development in modern textual criticism informs us that we should generally trust that scribes copied carefully. 

“1. Scribes typically copy their sources with fidelity so that ancestors and descendants are closely related

2. When scribes diverge from their primary source, it is more often because they have access to another source”

Ibid. 99

Taking into consideration this axiom, it is reasonable to try and make some determinations as to whether P75 and Codex Vaticanus have a “clean transmission” between them. I will be looking at the pregenealogical coherence of P66, P75, and Vaticanus below.

Using the INTF Manuscript Clusters Tool for John, we see that P66 has 59.9% pregenealogical coherence with P75 and 51% with Codex Vaticanus in the places compared. P75 has a 79.1% pregenealogical coherence with Codex Vaticanus in the places compared. This tells us that comparisons between P66 and Codex Vaticanus are not particularly relevant if we are trying to make the case that there is a clean transmission between the two. P75 is better, though if our objective is establishing a “clean transmission” between P75 and 03, we have to say that 79.1% pregenealogical coherence is strong enough to make this judgement. If we take into account that relationships with less than 78% are considered irrelevant for this analysis, the initial data does not bode well for Dr. Boyce’s case. 


Now, this is where my reader will have to think for themselves. Is Dr. Boyce justified in saying that there is a “clean transmission” between P75 and Codex Vaticanus? We can easily dismiss this claim between P66 and Vaticanus with 51% pregenealogical coherence. These two manuscripts agree in roughly the same places they disagree. In the case of P75, there is a 21% difference in the places compared. If we assume that the scribe of Vaticanus copied carefully, it seems more reasonable to say that he had access to other sources, rather than saying that he made errors in 21% of the places he copied. The simple conclusion is that no, there was not a “clean transmission” between P75 and Vaticanus. In other words, there are pieces missing to this puzzle, and we do not have those pieces. 

Now, to give my reader a picture to put this in perspective, imagine a puzzle that takes up the size of a coffee table. Now imagine that 22% of those pieces are either missing, or belong to another puzzle. It is possible that the scribe of Vaticanus had access to P66 or P75, but our data does not tell us that these were the only two sources used, if they were used at all. It is possible that Vaticanus shares a “clean transmission” with some other manuscript(s), but it is not responsible to say that those manuscripts are P66 or P75. According to Dr. Boyce in his opening presentation, we should be guided by what the evidence says. In this case, it does not appear that the evidence agrees with the claim made by Dr. Boyce in his debate with Dr. Jeff Riddle that P75 has a “clean transmission” up to Codex Vaticanus. There are simply too many pieces unaccounted for to responsibly make this claim. 

6 thoughts on “Is There Evidence of a “Clean Transmission” from P75 to Codex Vaticanus?

  1. To be clear, I never stated the relation between P66 and B. The clean transmission statement was only made of P75 and B. I mentioned P66 being important and early but that was about it. The stats are interesting just the same. Thanks for sharing


  2. “Reconsidering the Place of Papyrus Bodmer XIV-XV (P75) in the Textual Criticism of the New Testament”
    Brent Nongbri

    “Papyrus Bodmer XIV–XV (P75) …The evidence gathered in the present essay calls these conclusions into question by showing that both paleographically and codicologically, P.Bodm. XIV–XV ﬁts comfortably in a fourth-century context, along with the bulk of the other “Bodmer papyri” with which it was apparently discovered.”

    This is enough to discard the “clean stream” (or muddy puddle) claim.

    And there is more discussion on the Facebook group, Textus Receptus Academy.


    Steven Avery
    Dutchess County, NY, USA


  3. I had not heard of pregenealogical coherence before reading this article, but as soon as I started to understand the argument being used, it reminded me of the argument used to say that because we have 60% of our genes for protein in common with a mouse and 40% in common with a fruit fly, then it shows we must be related! Phooey! I might have some hydrogen in every cell of my body but that doesn’t mean I’m related to the Sun. Seems to me if a person believes in pregenealogical coherence then I have a piece of real-estate on Mars I would like to sell to them – at a bargain price of course.


    1. Interestingly enough, I read a huge dissertation by a biology PhD critiquing the CBGM. There is definitely a crossover.


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