That weird BBC reconstruction of Jesus' head.
The in post before the last, I talked a bit about oral tradition, Hebrew Matthew as an early collection of this oral tradition, and the development of Greek oral tradition as the Gospel moved into new contexts. Mark would then represent a written form of this phenomenon. This was not just any tradition, but, if the father's are to be believed, it was selections from the preaching of Peter masterfully arranged into a complete narrative, a document quite unlike Hebrew Matthew, which, I suggest, was a collections of sayings arranged topically, perhaps occasionally placed in a narrative context.
Now, the publication of Mark's Gospel would have had a great effect on the Greek Oral tradition, causing it to become much more stable in the communities where it was promulgated. Still, Mark's Greek isn't particularly good, it seems that native speakers often felt a need to correct him in the retelling of the same traditions, not to mention that independent oral traditions in Greek must have already existed, and probably also had an influence on the retelling of Mark. I'll get into evidence of this in a few paragraphs here. Let's get on to my favorite gospel now, Luke.
I like Luke because he approached the writing of his Gospel in the same way that I would have. He got as much evidence in front as he could, and tries to present it as accurately as possible. He seems to be a product of Hellenistic culture, and therefore shares many of the concerns that other western historiographers might. That's not to say he doesn't have an ideological agenda. It is to say that all historiographers have agendas. However, Western historiographers operate under the assumption that their argument will have the most force if it is grounded in verifiable facts. It appears to me, and to most others, that Luke knew the Gospel of Mark in some form, and possibly knew the man, John Mark, as well, if the traditional ascriptions of authorship are true. Luke follows Mark's chronology very closely (up until the passion narrative, where he prefers a different order) but he polishes up Mark's Greek.
Furthermore, it appears that he also had a Hebrew or Aramaic source in front of him, because he's often translating it very literally, and we can see the semitic syntax, especially in the sayings. Let's go ahead and call that Hebrew Matthew. But Luke was probably working with other semitic sources as well. One of those sources, again following the traditional view on authorship, would have been Paul, and whatever strain of Hebrew/Aramaic oral tradition was current in Pauline circles. From the first couple verses of Luke, it also seems very possible that he sought out eyewitnesses and used them as another source. He has no qualms about going against Mark's report when he believes he's got a better tradition, and he prefers almost always to make his own literal translations of semitic sources. It is also important to note that he did not attempt to fully preserve any of his sources, but to use all of them to create the narrative he wanted to create. Because Luke was came out a bit later and didn't follow any previous form of the Greek oral tradition, Mark continued to be more often quote for its familiarity, though sometimes in a polished form. Luke's main influence on the oral tradition was in the areas where Mark had not written, and this was still not so profound.
Some time later after the Greek oral tradition had really begun to crystallize, some anonymous saint came along and decided it would be worthwhile to preserve Hebrew Matthew in Greek (for which I am very grateful, being that it is lost in the original, unless there are bits of it preserved in Shem Tob's Hebrew edition of Matthew, a topic I'm not going to touch now). However, this wasn't all he did. He retained the structure of Hebrew Matthew for the sayings, but supplemented by Mark's narrative in polished Greek. In the sayings, he likes to follow Mark very closely where he can, sometimes fixing the Greek according the oral tradition. In other places, he follows, I think, different forms of the Greek oral tradition, which is sometimes influenced by Luke's translations of the content of Hebrew Matthew (and thence the so-called Q), and sometimes takes another form. Occasionally, he makes his own original translations, which, like Luke's, tend to be quite literal. It appears that this writer believed the Greek oral tradition to be authoritative, which is consistent with what we know of the early second-century fathers.
Because Matthew relied so heavily on the established Greek oral tradition for its wording, it was immediately popular in the church for its familiar sound, and quickly became the most quoted gospel (though I must admit, it may have gone the other way around, and it only seems that Matthew is quoted so often because he used the authoritative Greek oral tradition. It probably worked both ways, in reality), and was naturally placed first when it came time to order the Canon. Even today, The sayings of Jesus are most often recalled according to the Greek version of Matthew.
So finally, we are left today with Mark, a crude translation of Peter's version of the oral tradition, masterfully arranged into a thrilling historical narrative of a very eastern kind, Luke, the "historical-critical" Gospel, and Matthew, our only glimpse of Hebrew Matthew, and the preservation of the Greek oral tradition promulgated in early second century church. Course, we also have John, but that's something else. I don't even know where to begin with John.
(For those who want to know, I think the Western textual tradition of the gospels also preserves a lot of elements of the Greek oral tradition that are not found in the canonical Gospels. If this could be proven, their value in study of the historical Jesus would go up tremendously. Unfortunately, I don't have time to do this myself, working on an MA in OT at the moment. Perhaps one of you working on a graduate degree in New Testament could make a good project out of the Western text, seeing where it represents scribal corruptions of the original, and where it appears to represent a separate oral tradition. This topic could easily be a doctoral dissertation.)