B. H. Streeter's work, The Four Gospels: A Study of Origins (London: Macmillan, 1930), may be the single most consequential work of 20th century biblical scholarship for establishing what is now widely known as the "Two-Source Hypothesis": the idea that Matthew and Luke are literarily independent of one another and that they both relied on Mark and "Q" as two key sources for their respective Gospels.
B. H. Streeter
Streeter: Sure, Augustine's Theory Works, if Mark was a "Lunatic"
In The Four Gospels, Streeter has some remarkably harsh words for Augustine's (much earlier) theory that Mark published his Gospel after Matthew and was in fact Matthew's "abbreviator" (Latin breviator):
"Augustine did not possess a Synopsis of the Greek text conveniently printed in parallel columns. Otherwise a person of his intelligence could not have failed to perceive that, where the two Gospels are parallel, it is usually Matthew, and not Mark, who does the abbreviation.... [O]nly a lunatic would leave out Matthew's account of the Infancy, the Sermon on the Mount, and practically all the parables, in order to get room for purely verbal expansion of what was retained." (Streeter, The Four Gospels, 158).
Streeter: Sure, Luke Could have Used Matthew and Mark, if He Was a "Crank"
We find similarly rhetoric when Streeter turns his guns on the theory that Luke used both Matthew and Mark (a form of what is today known as the 'Farrer' Hypothesis).
"If then Luke derived this material [the Temptation narrative] from Matthew, he must have gone through both Matthew and Mark so as to discriminate with meticulous precision between Marcan and non-Marcan material; he must then have proceeded with the utmost care to tear every little piece of non-Marcan material he desired to use from the context of Mark in which it appeared in Matthew--in spite of the fact that contexts in Matthew are always exceedingly appropriate--in order to re-insert it into a difference context of Mark having no special appropriateness. A theory which would make an author capable of such a proceeding would only be tenable if, on other grounds, we had reason to believe he was a crank." (Streeter, The Four Gospels, 183)
I can't help but wonder if such hyperbolic rhetoric played a key role in making it very unfashionable to hold any theory that posited Mark or Luke's uses of Matthew as a source.
After all, who wants to side with a "lunatic" or a "crank"?
For a response to the latter criticism, see Marc Goodacre's brilliant study, The Case Against Q (London: T. & T. Clark, 2002).