Alexandrian Canon

The Alexandrian Canon hypothesis is the idea that Jews in Alexandria maintained a different, wider canon than Palestinian Jews. Whereas Palestinian Jews in the first century basically adhered to what would become the rabbinic canon of 24 books--attested, more-or-less, by Josephus at the end of the first century--Alexandrian Jews accepted all of these books and then some, especially the deuterocanonical books that are found in LXX manuscripts. The idea is often associated with Semler.

The main monograph that is always cited about the Alexandrian Canon is Albert Sundberg's dissertation (at Harvard) published as The Old Testament of the Early Church (1964), which attempted to undermine the theory. Sundberg's main arguments were that Alexandrian Jewish writers (e.g. Philo) show no signs of maintaining a canon wider than the Palestinian Jewish canon, and the Palestinian Jewish canon was not settled in the first century anyway, and the Dead Sea Scrolls show us that a large body of literature was considered sacred. This last point makes the Alexandrian Canon theory useless, because the theory is supposed to explain why Christians ended up with a wider canon than Jews, and it does so by saying Jews adopt the Palestinian Jewish canon whereas Christians inherited the Alexandrian Jewish canon (via the LXX). Sundberg said this scenario was not the reason Jews and Christians ended up with different canons, but rather there was no Jewish canon in the first century--neither in Palestine nor in Alexandria--there was just a bunch of religious literature. It was only after Judaism and Christianity split off from each other that each formed its own canon.

(Actually, Sundberg advocated the three-stage theory of canon development, whereby the Torah was canonized sometime in the fifth century BCE, and the Prophets were canonized maybe around 200, and the Hagiographa were canonized at the Council of Yavneh at the end of the first century CE. So, in the first century, Christians inherited from Jews a closed section of Torah and a closed section of Prophets and an open third section consisting of a wide array of religious literature. It was this third section that the two groups 'closed' in different fashions after their split. The Jews closed it at Yavneh, the Christians later on.)

Sundberg (pp. 18–19) says the theory of an Alexandrian canon was first formulated by John Ernest Grabe at the beginning of the eighteenth century in an edition of the LXX based on Alexandrinus. But Sundberg (p. 18 n. 47) reports that Grabe's work was not available to him (which is strange, considering Sundberg did his dissertation at Harvard--I would have thought Harvard had almost everything). So Sundberg didn't realize that the theory was actually not formulated by Grabe but by another fellow named Francis Lee, who wrote the Prolegomena to the second volume of Grabe's edition of Alexandrinus in 1719. Later scholars (post Sundberg) have been more precise in making this distinction. The second volume of Grabe's edition is available here; it doesn't have page numbers, but I think the relevant section is chap. 1 of the Prolegomena, Proposition 24, §§ 75–77.

The Alexandrian Canon idea was well accepted at the time of Sundberg's dissertation, and his work has proved to be a powerful influence against the hypothesis. A representative of the idea before Sundberg is Robert Henry Pfeiffer, one of Sundberg's teachers at Harvard whom Sundberg critiques throughout the monograph, especially at the beginning. (See Pfeiffer's Introduction to the OT, pp. 65–70.) Sundberg wanted to make the idea look like it had been around and widely accepted for a couple of centuries; apparently he exaggerated a bit. In a recent article (in this reference work, 2013) by Stephen Chapman we read in a note:

On the basis of the present study, it would seem that Sundberg, Canon (1964), misreads the history of scholarship when he characterizes the Alexandrian canon hypothesis as an unquestioned assumption prior to his own work in abolishing it. In fact, the hypothesis appears to have been widely known but largely unpersuasive throughout the nineteenth century. (685n118)

One final note about the Alexandrian Canon: it seems that the theory is making a comeback. While scholars largely abandoned the idea in the wake of Sundberg's monograph, several recent studies have sought to affirm it in some modified form. In a recent article (in this collection, 2014), Armin Lange, while arguing against the Alexandrian Canon idea, cites several recent scholars as favoring it (661–62): Hanhart (in the introduction to Hengel), Guillaume (pp. 26–31), Fabry (his contributions here and here). Most recently, Jan Joosten has come out in favor of it (article here, published here). 

I might comment on these recent defenses of the idea sometime in the future. 

Incidentally, the opposite position is also known in scholarship, such that the Alexandrian Jews did not have a bigger canon than the Palestinian Jews but rather a smaller canon, the Torah alone; see Carr (here, p. 35), Aejmelaeus (here). 

UPDATE: I see now that Chapman's characterization of Sundberg is unfair, since Sundberg does in fact recognize that throughout the nineteenth century the idea of an Alexandrian Jewish canon was not widely accepted in scholarship. See especially ch. 3 of his monograph, pp. 25–40. Sundberg shows that the Alexandrian Canon hypothesis could not prove persuasive as long as it was still generally believed that the Men of the Great Synagogue had settled the canon during the days of Ezra, a theory first formulated by Elias Levita in 1538 (e.g., p. 120; and see Ryle, excursus A). This idea was mortally wounded only in 1876 by Abraham Kuenen (see here for the reference). "The way was now open for the general acceptance of Semler's hypothesis of an Alexandrian canon that included the books of the Apocrypha as the Old Testament canon adopted by the Christian church" (Sundberg, p. 39). So, I think even in Sundberg's telling, the Alexandrian Canon hypothesis was popular for only about 60-70 years.