Reddit mentions of The Critical Edition of Q: A Synopsis Including the Gospels of Matthew and Luke, Mark and Thomas With English, German and French Translations of Q and ... French, German and Ancient Greek Edition)

I definitely wouldn't dispute that Q is a reality that, at this moment of scholarly consensus, is used to account for the textual parallels in Matthew and Luke. But my point is that this does not constitute "evidence of a second source" as such––it constitutes a theory that fits the data. A coherent theory is a useful thing that should not be tossed out necessarily, but a theory is not equivalent to evidence. My point about the textual remains that may or may not exist on the papyrus mummy mask mentioned in the article is that supposing that Q is part of the realia of early gospel traditions is turning a theoretical placeholder into a piece of evidence, i.e., turning a useful hypothetical into a material artifact. That kind of slippage is dangerous precisely because it requires a theoretical rigidity that, as scholarship is beginning to suggest, is not warranted by what we actually have.

Q as a hypothetical source is a wonderful mental tool that allows us to consider points of connection, overlap, and interrelationship in what was unquestionably a diverse oral tradition. Q as a definitive source for which there is no extra-textual evidence and no basis for assuming beyond form-critical speculation introduces a hornets nest of assumptions and theological speculation that imposes judgment over questions we could HARDLY begin to answer definitively.

This is to say, it is not "automatically non-existent" because it wasn't written down. It is "automatically non-existent" because it's existence was always tenuous and never had any substance to it in the first place. The problem is that scholars, some of whom are lazy and others of whom are willing to entertain speculative claims beyond what can actually be substantiated, have created a certainty around Q to the level that there is even a Hermeneia commentary on the "document." While this might be an interesting speculative exercise, it is not warranted by an unsubstantiated document––it amounts to surmising about a passing breeze, or, in a more conspiratorial vein, to scouring the Great White North for Yeti. When searches presume about facts that are not in evidence, it leads to misinformed conclusions.

This emphatically is not my area of expertise in the study of the New Testament and Early Christianity. But I would point anyone interested to the materials conveniently gathered by Mark Goodacre here: http://www.markgoodacre.org/Q/ (admittedly, Goodacre is a Q-critic, and he has written lengthily on the subject of Markan priority and against the theoretical underpinnings of the four-source hypothesis. On the other side of the equation, I would also point you to the very Hermeneia commentary I reference, in which the exhaustive bibliography (especially the work of Kloppenborg, one of the authors) gives good places to go to find some of the kinds of rebuttles that Q-apologists might use to respond to critics and skeptics. (here: http://www.amazon.com/The-Critical-Edition-Translations-Historical/dp/0800631498)

Hey, I'm at an internet cafe so I'll try to answer the other part of your question:

>why (do) the gospel accounts describe events differently (Jesus' last words, for instance), and why some of them aren't just contrary but actually contradictory (did Jesus carry his cross in silence or did he hold conversations along the way? Who discovered the empty tomb first and did they tell anyone or not?)

The short answer is "we don't know." However, scholars can make educated guesses.

Jesus' earliest message is thought to have been transmitted via itinerant preachers quoting from a "document" called Quelle (German: "Source"), of which no copies survive on their own, although reconstructions have been attempted. Q source is thought to be responsible for the overlapping teaching and miracle stories in Matthew and Luke which is not found in Mark. John did not rely on this source in any discernible way. I personally have some serious reservations about this theory, chief among them that no copies of this document survive, while thousands of copies of the NT do, but we'll work with it in this case.

Given that starting point, which (let's assume) contained a more or less accurate account of Jesus life and teaching as people closest to him (his original followers) had remembered it, the best (but by no means a perfect) way to think about the Gospels would be to imagine them as being like movies which are "based on a true story." Some chronology in these movies would be rearranged to heighten drama, some discourses or statements might be made more poignant to indicate foreshadowing (for a great example of this, read Luke, where statements like Acts 1:8 serve perfectly as a thesis for the book), and some teachings paired specifically to miracles to make a point. This sort of thing explains some of the rearrangements very well-in the Synoptic Gospels, Jesus cleanses the temple at the end of his life. This makes sense, because it seems to be why he was arrested and killed. However, in John, it comes early, probably because it is being used to set the stage for Jesus' radical ministry. However notice the bottom line here is this: regardless of when it happened, or what the implications are that it happened, the gospels agree that the cleansing of the temple did happen.

Each gospel author has a theological point to make-about money and social class (Luke), the Kingdom of Heaven (Matthew), The Kingdom of God (Mark) etc. We have no way of knowing how great or small the degree of creative license is. Scholars generally concede that a large number of the statements and acts in the gospels are real doings of Jesus-dying on the cross, the sermon on the mount, radical teaching concerning the temple, etc. However, to really get to the bottom of something like this with absolute certainty is an impossible task.

However, this does not mean that the gospels are fabrications, or fundamentally unreliable. Nobody doubts that a lot of Herodotus or Thucydides were typically basing their accounts on factual events, but speeches and acts would often be crafted or modified to conform to expectation. Additionally, the gospels gain considerable credibility when compared to other ancient documents. Mythologizing often takes place in ancient stories, but it is unusual (some have said singular) for it to have happened so soon after a person's death (30-50 years), and for it to involve deification in the case of a Jewish Rabbi is certainly a total anomaly in history. Obviously, some faith and discernment is needed for the modern mind to accept the supernatural parts of the gospels, but in general their contradictions don't point to the sort of outrageous fabrication some detractors assume.