Below is another Amazon review just posted, of The Birthing of the New Testament: The Intertextual Development of the New Testament Writings by Thomas Brodie.
This is a landmark book in biblical studies, not so much because of its Proto-Luke hypothesis as because of its first 9 chapters that present and justify the author’s methodology. These chapters are clearly and effectively argued, and they are extremely important because they undermine key parts of the paradigm subscribed to by most biblical scholars. Much of this has been argued elsewhere of course, but this is to my knowledge the most comprehensive and effectively argued attack on the idea of oral tradition that has yet been published anywhere, and it should be read by anyone who is inclined to take that idea seriously.
These nine chapters offer an account of the incredible variety of ways that people in the ancient world created new works of literature by copying old ones; they refute the idea that the Old Testament or New Testament were unique exceptions to this pattern; they create and defend a series of criteria that scholars can use to determine when one literary work is dependent on another; they provide a brief history explaining how the process of creating literary works worked in the ancient world; they refute the idea that the New Testament authors could have been so isolated that each could somehow write in complete ignorance of the others’ works; and they reach a well-substantiated conclusion that much of the New Testament – even including the epistles of Paul — was produced by a single far-flung community rather than by isolated individuals.
The remainder of the book presents Brodie’s application of his methodology at some length, including his Proto-Luke hypothesis. I personally found this rather more of a mixed bag than the first nine chapters. In particular, Proto-Luke seems little different from Q or oral tradition insofar as it amounts to an attempt to explain by appealing to an unknown quantity for which there is actually no hard evidence. Nevertheless, this does not reflect negatively at all on Brodie’s presentation of his methodology. The very fact of "authorial complexity" which he so forcefully defends in the first part of the book means that no criteria no matter how well thought out and applied will reliably tip the hand of an author who was not inclined to tip his hand.
The book is very long and is written largely by a scholar for scholars; nevertheless I highly recommend it to anyone who is interested in learning more about the foundations of biblical scholarship, especially with regard to the Gospels or attempts to find "the historical Jesus." At the very least, read the first nine chapters. Those chapters alone are worth the cost of the book. Regardless of whether you agree with everything you read there, when you’re done you will be less inclined to blindly accept statements by other biblical scholars that are presented as fact, but are actually highly questionable.