On Luke's use of sources

I have enjoyed reading some of April DeConick's questions and reflections on Luke and History in The Forbidden Gospels Blog. In particular, a post headed Is Luke a Trustworthy Historian? asks:

Why is Acts written off today as a Lukan myth with little or no historical value? Why do scholars who wish to argue for the historicity of elements of Acts have to go through an inordinate amount of justification before doing so?

and there are a series of interesting points that focus the question, and I would like to comment on these points, even though doing so takes me off at tangents from April's main points.

1. When Luke uses Mark, he does not rework Mark as much as Matthew.

I did a double take when I first read this, thinking that perhaps April had joined us in the Q sceptical camp, but then I realized that I was reading it incorrectly! It is "he does not rework Mark as much as Matthew (reworks Mark)" and not "he does not rework Mark as much as (he reworks) Matthew". Nevertheless, I think the comment is debatable and for several reasons. First, Matthew features much more of Mark than Luke does; or, to put it another way, Luke omits much more of Mark than Matthew does. Second, the perception that Luke generally retains Mark's order more carefully than Matthew does is problematic. Matthew's rearrangement of Mark is primarily limited to Matt. 8-12. After Matthew 13 // Mark 4, Matthew follows Mark's order very closely. Luke is radical in some of his treatment of Mark, especially drawing forward the Rejection at Nazareth (Luke 4.16-30) from a much later point in Mark, and drawing forward the Anointing (Luke 7.36-50) from a later point still. (I have more on this in The Case Against Q, 86-90). Third, I would draw special attention to the Passion Narratives in the three Synoptics. Luke departs far more from Mark here than does Matthew. It is worth reminding ourselves that B. H. Streeter and Vincent Taylor conceived the Proto-Luke theory on the basis of Luke's massive departures from Mark in material like that.

2. When Luke uses Q, Q-scholars tell us that he retains Q better in terms of verbage and order than Matthew. In fact, our reconstructed Q is versed according to Luke.

From my reading of Q scholarship, I think this overstates the standard view. It is consensus in Q scholarship that Luke retains the order of Q better than does Matthew, but opinions are divided on how far Matthew and how far Luke retains Q's wording and there is no real tendency in either direction, at least if we are to go on the work of the IQP. With respect to the Lucan chapter and verses getting used for referring to Q, a practice I have criticized (e.g. in Case Against Q, 8), it is important to note that it has always been said that this is done for convenience and without prejudice to decisions about whether or not the order of a given pericope is better reflected in Luke or Matthew.

3. Luke tells us in the beginning of his gospel that he relied on older sources to rewrite the Christian narrative which we apparently trust given our hypothesis that Luke is a second edition of Mark.
4. If we think that Luke used Mark and Q as literary sources, wouldn't the best assumption be that he also used older traditional sources for the composition of Acts?
5. If 4 is valid, then shouldn't we be trying to figure out what those older traditions are and what they tell us about Christianity earlier than Luke?

These are interesting points. One thing that is worth taking seriously is to find out what we can about Luke's compositional and redactional habits from an analysis of his Gospel sources Mark and (I would say) Matthew and to learn from them in working out how he is writing in Acts. I argued on this blog a while ago (A Chronological Clue in Acts 9.25, The Jerusalem Council: Gal. 2.1-10 = Acts 15 and The Jerusalem Council: Gal. 2.1-10 = Acts 15: Response to Critics) and one day I will publish on this, that where Luke has Paul visiting Jerusalem in Acts 9, clearly out of sequence when we look at Galatians 1, he has brought the account forward in his narrative from its natural location three years later, just as he draws forward the Rejection at Nazareth in his Gospel from its Marcan location later in the ministry. My own feeling is that the more familiar one gets with Luke from studying his use of sources in the Gospel, the more light it sheds on the way he behaves in Acts, where we have Paul's letters as a useful point of comparison.