Luke is an expansion of Mark. There can be no doubt about this. So what does that make the Marcionite gospel which is reported originally in Irenaeus's (now lost) Adversus Marcionem which is only partially preserved (and translated into Latin) in Tertullian's text of the same name? If we wholly absorb what Tertullian is telling us at face value i.e. that (a) there were the apostles Matthew and John (b) there were the so-called "apostolics" Mark and Luke and (c) this "evangelic Tetrad" eventually produced the gospels - something doesn't quite add up.
The arguments that Irenaeus develops in Adversus Haereses to justify the "appearance" of four gospels resemble the Marcosian myths about a "primal Tetrad." This is the first sign of the late development of the four gospels. Why does Irenaeus need two primal gospels (Matthew and John) to explain the origins of two derived gospels (Mark and Luke) when Mark is obviously the source of all the other gospels? There are clear signs that the Alexandrian tradition of Clement took Mark to be a "primal" gospel (if not "the" primal gospel). Even if an attempt to deny this is made (as part of an accepted conspiracy theories of sorts involving a discovered letter of Clement) not only is the primacy of Mark expressed in Clement's famous homily on Mark 10:17 - 31, the primacy of Mark is a historical fact.
Either the ancients were universally ignorant of this fact or the Alexandrians were aware of it and we don't admit this because it calls into question what became the "Roman orthodoxy" and its Matthew-based canon. Why does Irenaeus think Matthew was the gospel from which all other gospels developed? In point of fact Irenaeus never works hard to develop this claim. Instead he just appropriates the gnostic myth of the Primal Tetrad and adapts it to depreciate Mark and Luke as inferior apostles (they were "apostolics" again an obvious play on the name Marcionites gave to their canon as a collection from Paul) and Mark and Luke as gospels.
But is it too much to suggest - leaving behind the question of whether canonical Matthew and John ever had lives independent of Irenaeus's canon - that this pseudo-gnostic arrangement (i.e. the gospel Tetrad) was developed purely as a means to subordinate Mark and Luke. If we map the twin pairing of "Matthew and John" and "Mark and Luke" on to the positions held by Bythus and Sige and Nous and Aletheia, or Logos and Zoe, Anthropos and Ecclesia, or Anthropos and Ecclesia, Logos and Zoe (depending on which system you look at) there seems to be an undeniable sense that "Luke" sits in the position of the fallen Sophia (of course in the "specific" understanding of each reported "sect" this is only true in a general sense, but it is undeniably there).
Luke then is almost put out there as the gospel which was predestined to fall "victim" to corruption. In other words, presuming as we must that Marcion preceded the "four gospel set" concept that was promoted by Irenaeus (simply because Marcion is ever present in Irenaeus's reactionary system) a "restored Luke" mirrors the fall and redemption of Sophia in gnostic myth. The next step from this understanding is to wonder, "could someone like Irenaeus have at once condemned the gnostics for developing 'false-gnosis' regarding heavenly powers but ultimately adapted these same condemned myths for the holy canon of gospel texts of the Catholic Church? No I don't believe that. So who invented this "Tetrad of gospels" out of the "Tetrad of aeons"? Why not the same Alexandrians whom Irenaeus condemns?
The real force here is that Irenaeus clearly makes hostile verbatim citations from Clement of Alexandria's Stromateis - assuming them to be written by Mark the (recent) Valentinian. Clement himself makes reference to Matthew and Luke (and likely John) all the while hinted at Mark's primacy. He makes statements that the gospels with the genealogies "came first" all the while hinting at Mark's superiority. His reference to Luke in the Stromateis:
And to prove that this is true, it is written in the Gospel by Luke as follows: And in the fifteenth year, in the reign of Tiberius Cæsar, the word of the Lord came to John, the son of Zacharias. And again in the same book: And Jesus was coming to His baptism, being about thirty years old, and so on. And that it was necessary for Him to preach only a year, this also is written: He has sent Me to proclaim the acceptable year of the Lord . This both the prophet spoke, and the Gospel.
is cited verbatim by Irenaeus in Book Two as being "typical" of the way heretics misrepresent the ministry of Jesus.
I would like the reader to at least consider that these words of Clement were the original source of Irenaeus's idea that Marcion or Marcionites had a "false version" of Luke which only began with "And in the fifteenth year, in the reign of Tiberius Cæsar ..." I think a version of Luke circulated in antiquity which began here. I think Ephraim witnesses it. But that isn't the point here. What I am asking the reader to consider is whether Irenaeus's original attack against "Marcion" (whomever that was) simply assumed that Luke began here. Very little is made even in Tertullian's Adversus Marcionem about the missing material from chapters 1 through 3 (much less than would be expected if one wanted to establish Marcion as a falsifier of Luke.
In point of fact, little of Tertullian's Book Four is devoted to this very argument. We can almost read Tertullian as holding up a common gospel - a gospel held in common with Clement of Alexandria - which began with the words "in the fifteenth year, in the reign of Tiberius Cæsar ..." which was preserved still in fourth century Osroene which still lacked the birth narrative but could be read as a fuller "expanded" Mark. What does this mean for our revaluation of Marcionism? I think Marcionism, despite which is written in the opening lines of Adversus Marcionem, originally derived from Alexandria.
