I mentioned that I gave a paper in Oslo some weeks ago on the issue of manuscripts and the synoptic problem. While it was the issue of manuscripts and variant readings that was the focus of my attention, writing this paper forced me to revisit some foundational scholarship on the gospels and challenged me to try to visualize some data for a general audience. I did so using Venn Diagrams. Now I see that Mark Goodacre, in a series of posts (here, here, and here) prompted by the insightful work of Matthew Larsen, has also been experimenting with Venn Diagrams to model synoptic relationships (see also the interesting contribution by Joe Weaks).
While Goodacre has been mainly working with relationships between two gospels, I wanted to try to model all three synoptic gospels together using such a graphic. I discovered, however, that you can’t really represent things quite accurately with three circles. To get the model to fit the data, you would need shapes other than perfect circles (this would be a Euler Diagram). So instead of perfect representation, I have chosen to stick with the Venn Diagram (albeit a rough one) to try to model the overlap of the three synoptic gospels.
I should also note that I used a different source of data from that used by Larsen and Goodacre. Rather than counting stories in the Nestle-Aland Synopsis, I relied on the word counts in the old study by A. M. Honoré, “A Statistical Study of the Synoptic Problem,” Novum Testamentum 10 (1968), 95-140. Using those numbers (which differ in that they more nearly indicate the relative length of the gospels and show Luke preserving a bit less of Mark), I came up with this rough diagram:
Now, the most widely held “solutions” to the Synoptic Problem is the so-called “Two Source Hypothesis” (or “Two Document Hypothesis”), which, in the words of John Kloppenborg, can be summarized as follows:
“Stated succinctly, the Two Document hypothesis [2DH] proposes that the gospels of Matthew and Luke independently used Mark as a source. Since Matthew and Luke share about 235 verses that they did not get from Mark, the 2DH requires that they had independent access to a second source consisting mainly of sayings of Jesus. This, for want of a better term, is the ‘Sayings Gospel,’ or, ‘Q’” (John S. Kloppenborg Verbin, Excavating Q: The History and Setting of the Sayings Gospel [Minneapolis: Fortress Press, 2000], 12-13).
One of the reasons I wanted to stick with the circles in the Venn Diagram is to illustrate a particular point about the Two Source Hypothesis. If we color the circles in a way that highlights the material in the so-called “Q-Source” (the material common to Matthew and Luke but not present in Mark), we can see this segment quite clearly:
One of the main problems for proponents of the Two Source Hypothesis is the existence of agreements between Matthew and Luke against Mark. According to the Two Source Hypothesis, this shouldn’t happen (Matthew and Luke are said to have used Mark independently of one another; so agreements between them against Mark should be rare or non-existent). Some proponents of the Two Source Hypothesis try to explain some of these agreements by suggesting that there was some “overlap” between Mark and Q, and that Matthew and Luke have sometimes chosen the Q version of a passage or phrase insead of the Markan version. They call such material Mark-Q overlaps, or something similar. So here is where I think our Venn Diagram becomes useful. If we adjust it to allow for overlap between Mark and Q, we can see what happens:
The more Mark-Q overlap we allow, the more Q begins to look like Matthew (and, to a somewhat lesser extent, like Luke). The more Q looks like Matthew, the less Q seems to be a necessary hypothesis, and the more it seems like the Farrer-Goodacre Hypothesis (Markan priority without Q) seems to be the more viable solution to the synoptic problem.
This point has of course been noted by many students of the synoptic problem, but I think the Venn Diagram really vividly illustrates the idea and helps it to sink in.