The synoptic problem concerns the literary relationships between and among the first three canonical gospels (the Gospels of Mark, Matthew, and Luke), known as the Synoptic Gospels (from the Greek 'syn,' meaning "together," and 'optic,' meaning "seen"). Similarity in content, word choices and event placement indicates some kind of literary interrelationship.
The synoptic problem concerns how this interrelation came to be and the nature of the interrelationship itself. Any solution must account for the similarities and differences in content, order, and wording. Possible solutions speculate either a direct relationship (one Evangelist possessed one of the gospels) or indirect (two Evangelists having access to a shared source). The sources may be written or oral; single or multiple.
This section is a brief overview of current speculative solutions to the Synoptic Problem including scholarly thought first proposed in the 1800s and traveling back through traditional church history and church views citing the writings of the ancient church fathers. Most modern study focuses on the two-source hypothesis.
Other theories usually posit more hypothetical and proto-sources. For example, Boismard calls for seven hypothetical documents, one of them a form of Q.
A handful of researchers, such as Eta Linnemann, argue that each of the evangelists are independent of one another and that the apparent literary similarities are merely coincidental. This theory is in the character of the fundamentalist or literalist Christian belief that the whole Bible, including the Gospels, was inspired directly by the Holy Spirit and that therefore no intermediate or source documents between books are required because "all scripture is God-breathed" ().
Agreement in the order of the content is the strongest indication of a documentary dependence, especially when the agreement touches topical arrangements instead of chronological (e.g., both Matthew and Mark relate the death of John the Baptist in a flash-back). Therefore most scholars have not found purely oral theories plausible. The pattern of order is quite different between the Triple and Double traditions.
In the Triple Tradition, the order (or arrangement) of the pericopes is largely shared between Matthew and Mark or Luke and Mark or among all three. It is rarely the case that Matthew and Luke agree against Mark in arranging the Triple Tradition. This formal property means that Mark is a middle term between Matthew and Luke. Specifically, the following scenarios are logically possible:
(1) K (2) M (3) L (4) M L/ K K /M L L M K
There is an additional fact about the arrangements of the Triple Tradition: Mark's order is almost always supported by either Matthew or Luke. This lends strength to the Griesbach Hypothesis [scenario b(4)], but that support is weakened by Tuckett's mathematical observation that the relatively rare deviations of either Matthew or Luke from Mark's order means that this observation is not statistically significant. Tuckett's model may be criticized for assuming randomness on part the later redactors (departures from a source are equally likely), but since Matthew's deviations are toward the beginning and Luke's are towards the end, it is not surprising that both Matthew and Luke rarely re-ordered the same Marcan pericope.
The agreement in order within the Double Tradition, however, is much weaker, mostly in the Sermon on the Mount/Plain, leading scholars to favor an indirect relationship for the Double Tradition. Thus, Matthew and Luke copied independently a sayings collection called Q. On the other hand, there is enough order in Q to argue that Q is a documentary source. Those other theories which do not hypothesize a shared sayings source usually assume that Luke copied the Double Tradition from Matthew.
A close comparison of the wording within the Triple Tradition shows that Matthew and Mark are usually quite close, with Luke being somewhat further. To the extent that Luke agrees in wording at all with the other two, it usually is with both or with Mark. Luke's agreements with Matthew against Mark, the minor agreements, are less frequent but not insignificant.
The role of the minor agreements is significant in as much as they suggest that Luke and Matthew might not be independent from one another. However, culminating in 1924, Streeter was able to show, to the satisfaction of most of the scholars of the time, that these "minor agreements" are largely trivial, coincidental, or attributable to textual corruption. Streeter's work allowed the Oxford School to replace the Ur-Markus of Holtzmann's 1863 Two-Source Hypothesis with the canonical Mark.
Griesbach's explanation of Mark's redactional procedure predicts that Mark should more agree with the Evangelist he currently is copying. Overall this is true, but often Mark prefers Matthew in areas he should be more like Luke.
As with other ancient texts, the fact that Mark's wording is usually fuller than either Matthew's or Luke's can be taken as buttressing either the priority or the abridgment arguments. In the priority perspective, the later writers simplified Mark's narration in their borrowing; in the abridgement argument, Mark would have amplified the other writers. Mark is also felt by some to be more "primitive" than either Matthew or Luke, thus arguing for priority, though there are also arguments for Matthean priority (e.g. being more Jewish), or that if Mark were editing two gospels together, his Greek might become more choppy and poor. This area of the synoptic problem has thus been riddled with reversible and inconclusive arguments, illustrating the often subjective character of such interpretations.