Question About the Synoptic Problem and the Priority of Matthew

[Tharmas]

I am reading a book I hadn’t read before by my favorite New Testament scholar, the late Burton Mack. It’s a study of the hypothetical Q document called The Lost Gospel: The Book of Q and Christian Origins.

In it, Mack gives a brief overview of New Testament scholarship from John Locke up to the 1980s, when Mack wrote (pub date 1993). The Q hypothesis shows up in the mid-19th century as a resolution to the “synoptic problem,” which is the relationship of the three synoptic gospels to each other.

It was noted that Matthew and Luke agree only when they are following/copying Mark. Material in Matthew and Luke but not in Mark include the “sayings" of Jesus, including parables, etc. The conclusion was that Mark was written first of the three (“Markan priority”), and that Matthew and Luke used two sources, Mark and an unknown sayings gospel that scholars labelled “Q”. This is the “two source” hypothesis, and according to Mack has been thoroughly tested and analyzed and is now accepted by most scholars.

Further support for the hypothesis came with the 1945 discovery of The Gospel of Thomas, which showed that indeed sayings Gospels did exist, even if a manuscript specifically of Q had never been found.

I myself am persuaded by the Q hypothesis and Markan priority.

However, Matthew as the first Gospel is the traditional order, and I understand that there are still scholars who promote that idea. My question for anyone out there is what are the essential arguments for Matthew being first?

 

[Politesse]

Why would the gospels necessarily need to be anthologized in publication order? When I was in seminary fifteen years back, Markan priority seemed to be pretty generally assumed. But it seems to me that monkeying with the now-standard order of the carious canons would be more confusing than revelatory, for reasons of habit if nothing else.

 

[Tharmas]

Thanks for your reply, Politesse. I’ll put you down as a traditionalist: Matthew is primary because it’s always been that way.

I take your point, and it certainly simplifies things. On the other hand, no one to my knowledge is suggesting that we literally reorganize the Bible.

The knowledge to be gained by the fact that Mark is most likely the first of the Synoptics gives us a deeper understanding of early Christianity, just as the realization that the (genuine) Pauline epistles pre-date the Gospels gives us a window on early Christianity.

Where Mack is heading, I believe, is a new translation/recreation of Q that will give us a view of the Jesus movement before “Christ,” before Apostles, before it became a church. He wants to put Christianity back in the contexts of early first century Galilee. I hope to find that interesting.

 

[Politesse]

It's not so much that I'm a blind traditionalist, as that I don't think attempting yet another rearrangement of the Gospels is likely to change anyone's perception of their contents. As you seem to grok actually, given your next sentence.

I also think we are unlikely at this point to encounter meaningful proof of either Markan or Matthean priority. We could unearth Luke's private journal tomorrow, with an entry that reads "today I published some annotated copies of Marks gospel and learned from the scriptorium that that tosser Levi beat me to the punch five months ago", and all it would accomplish would be to launch a debate about the journal's veracity.

I do share your interest in Burton Mack's scholarly legacy though.

 

[Tharmas]

Thanks for the expansion of your opinion. However, I still disagree. Perhaps I’m too much a fan of over-arching theories and explanations, but I find that the preponderance of the evidence supports the two-source hypothesis and the existence of Q.

In my opinion, what we have to gain by examining the hypothetical Q is a new window on the past, and on Christian origins.

I did enjoy your thought experiment about discovering Luke’s private journal, that it wouldn’t change anyone’s mind.

 

[Swammerdami]

I've no expertise on this topic but have done some recent readings. Three comments:

1. While the Gospels were finalized after 70 AD, parts of Mark were written before the Fall of Jerusalem.
2. Matthew, Luke and especially John have portions written originally in Aramaic. These include sections common to Matthew and Luke. Was "Q" Aramaic?
3.Much of the synoptic Gospels came from a common source ("proto-Mark"(?)) Is it clear which of the three is closest to the common source? Shouldn't it be possible to guess which is closest by careful reading?

For example, in the story of the swine drowning in a lake the spirit names itself "Legion" but not in Matthew. Did Matthew delete this detail from the common source, or did the other two Gospels add it? Similarly Matthew places the incident in the region of the Gadarenes, while the other two place it in the region of the Gerasenes. What are these place-names in the original Greek?

 

[Tharmas]

I've no expertise on this topic

You and me both.

I have not read much about proto-Mark. I’d be curious for a reference.

My author, Mack, in the book I am reading about Q, goes to great lengths to divorce Q from the later Gospel narratives, trying to show what Christianity looked like before the narratives were created. Q is mostly a collection of sayings and teachings of Jesus, which the gospel of Mark mostly omits.

Mack does seem to assume that Q was originally an Aramaic document, but he doesn’t dwell on that fact. Looking ahead, he comments that “Son of Man” is a literal translation of an Aramaic idiom meaning “person” or “human” and is used as a reference to oneself.

Mack creates a demographic picture of Galilee as a multi-cultural, multi-lingual outpost where Jewish culture coexists with Persian, Samaritan and Greek cultures.

 

[Tigers!]

I have found the Farrer Hypothesis to be most satisifying i.e The Farrer hypothesis suggests a simpler model of literary dependence, with Matthew and Luke directly relying on each other's work, in addition to Mark. No need for a unknown document 'Q' or otherwise.

 

[Swammerdami]

I have found the Farrer Hypothesis to be most satisifying i.e The Farrer hypothesis suggests a simpler model of literary dependence, with Matthew and Luke directly relying on each other's work, in addition to Mark. No need for a unknown document 'Q' or otherwise.

Even with no specific evidence, the existence of prior sources seems most parsimonious. Matthew and Luke were supposedly written 50+ years after the Crucifixion -- that's a long time for detailed narratives to survive in purely oral form. (That late dating IS controversial. There are arguments for an earlier dating of much of the works, with allusions to the Temple's destruction possibly added by later copyist/editors.)

But there is specific evidence for a written Aramaic source used independently by both Matthew and Luke. Compare Luke 11:39-41 with Matthew 23:26. Neither could have borrowed from the other. Instead Matthew correctly translated Aramaic 'dakkau' (to cleanse), while Luke misread the original as 'zakkau' (to give alms).

 

[Tigers!]

I have found the Farrer Hypothesis to be most satisifying i.e The Farrer hypothesis suggests a simpler model of literary dependence, with Matthew and Luke directly relying on each other's work, in addition to Mark. No need for a unknown document 'Q' or otherwise.

Even with no specific evidence, the existence of prior sources seems most parsimonious. Matthew and Luke were supposedly written 50+ years after the Crucifixion -- that's a long time for detailed narratives to survive in purely oral form. (That late dating IS controversial. There are arguments for an earlier dating of much of the works, with allusions to the Temple's destruction possibly added by later copyist/editors.)

But there is specific evidence for a written Aramaic source used independently by both Matthew and Luke. Compare Luke 11:39-41 with Matthew 23:26. Neither could have borrowed from the other. Instead Matthew correctly translated Aramaic 'dakkau' (to cleanse), while Luke misread the original as 'zakkau' (to give alms).

If the written Aramic source was Mark then parsimony is kept and no need to introduce Q.

 

[Swammerdami]

I have found the Farrer Hypothesis to be most satisifying i.e The Farrer hypothesis suggests a simpler model of literary dependence, with Matthew and Luke directly relying on each other's work, in addition to Mark. No need for a unknown document 'Q' or otherwise.

Even with no specific evidence, the existence of prior sources seems most parsimonious. Matthew and Luke were supposedly written 50+ years after the Crucifixion -- that's a long time for detailed narratives to survive in purely oral form. (That late dating IS controversial. There are arguments for an earlier dating of much of the works, with allusions to the Temple's destruction possibly added by later copyist/editors.)

But there is specific evidence for a written Aramaic source used independently by both Matthew and Luke. Compare Luke 11:39-41 with Matthew 23:26. Neither could have borrowed from the other. Instead Matthew correctly translated Aramaic 'dakkau' (to cleanse), while Luke misread the original as 'zakkau' (to give alms).

If the written Aramic source was Mark then parsimony is kept and no need to introduce Q.

In addition to the “Woe to you, teachers of the law and Pharisees, you hypocrites!" passages, Matthew's Sermon on the Mount has strong evidence that it was translated from Aramaic. Note that Luke has much of the same material ("Sermon on the Plain"), again with evidence that the translations from Aramaic were done independently of Matthew's. (The Epistle of James -- sometimes regarded as the earliest-written book of the New Testament -- also incorporates parts of the Sermon on the Mount.)

And neither the Sermon on the Mount, nor the "Woe to you hypocrites" passages are present in Mark's Gospel. I'm unaware of any Aramaic allegations applying to Mark's Gospel, but some consider John's Gospel to be the "most Aramaic" of the four Gospels.

 

[Tharmas]

Mack ends up a little bit “out there,” at least in my opinion. He demonstrates that Q comprises different layers of composition, showing Jesus first as a Cynic-like wandering philosopher who generates a collection of pithy aphorisms, then as a teacher instructing his flock, until he is shown as an Apocalyptic prophet and finally (with the introduction of John the Baptist) as a messiah, becoming “Christ.”

Mark combines all these different Jesuses together into one narrative, adding the passion narrative. Matthew goes even farther, creating the complete Christian myth. Q was superseded and disappears from history.

Mack spends some time investigating the books of the New Testament in light of the mythic layers he discovers in Q.

Where he goes over the top is in his conclusions, that his deconstruction of the layers of the Christian myth will force a public recognition that it is all myth and not history, and force a reevaluation of the American myth as well, and create some kind of new society. It’s not going to happen. As they say, “follow the money.”

 

[Tigers!]

Mack ends up a little bit “out there,” at least in my opinion. He demonstrates that Q comprises different layers of composition,

If we have no extant copy of Q, nor any confirmed snippets of it then how can one show it has different layers of composition?

showing Jesus first as a Cynic-like wandering philosopher who generates a collection of pithy aphorisms, then as a teacher instructing his flock, until he is shown as an Apocalyptic prophet and finally (with the introduction of John the Baptist) as a messiah, becoming “Christ.”

Mark combines all these different Jesuses together into one narrative, adding the passion narrative. Matthew goes even farther, creating the complete Christian myth. Q was superseded and disappears from history.

It still has never been confirmed that Q actually existed in its claimed form.

Mack spends some time investigating the books of the New Testament in light of the mythic layers he discovers in Q.

Where he goes over the top is in his conclusions, that his deconstruction of the layers of the Christian myth will force a public recognition that it is all myth and not history, and force a reevaluation of the American myth as well, and create some kind of new society. It’s not going to happen. As they say, “follow the money.”

 

[Tharmas]

I have found the Farrer Hypothesis to be most satisifying i.e The Farrer hypothesis suggests a simpler model of literary dependence, with Matthew and Luke directly relying on each other's work, in addition to Mark. No need for a unknown document 'Q' or otherwise.

Even with no specific evidence, the existence of prior sources seems most parsimonious. Matthew and Luke were supposedly written 50+ years after the Crucifixion -- that's a long time for detailed narratives to survive in purely oral form. (That late dating IS controversial. There are arguments for an earlier dating of much of the works, with allusions to the Temple's destruction possibly added by later copyist/editors.)

But there is specific evidence for a written Aramaic source used independently by both Matthew and Luke. Compare Luke 11:39-41 with Matthew 23:26. Neither could have borrowed from the other. Instead Matthew correctly translated Aramaic 'dakkau' (to cleanse), while Luke misread the original as 'zakkau' (to give alms).

If the written Aramic source was Mark then parsimony is kept and no need to introduce Q.

Except Mark doesn't include either Luke's or Matthew's verse, which is part of Swami's point. I'll get back to you later with more of the arguments for Q that have been proposed by New Testament scholars.

 

[Tigers!]

I have found the Farrer Hypothesis to be most satisifying i.e The Farrer hypothesis suggests a simpler model of literary dependence, with Matthew and Luke directly relying on each other's work, in addition to Mark. No need for a unknown document 'Q' or otherwise.

Even with no specific evidence, the existence of prior sources seems most parsimonious. Matthew and Luke were supposedly written 50+ years after the Crucifixion -- that's a long time for detailed narratives to survive in purely oral form. (That late dating IS controversial. There are arguments for an earlier dating of much of the works, with allusions to the Temple's destruction possibly added by later copyist/editors.)

But there is specific evidence for a written Aramaic source used independently by both Matthew and Luke. Compare Luke 11:39-41 with Matthew 23:26. Neither could have borrowed from the other. Instead Matthew correctly translated Aramaic 'dakkau' (to cleanse), while Luke misread the original as 'zakkau' (to give alms).

If the written Aramic source was Mark then parsimony is kept and no need to introduce Q.

Except Mark doesn't include either Luke's or Matthew's verse, which is part of Swami's point. I'll get back to you later with more of the arguments for Q that have been proposed by New Testament scholars.

Yet if Mark had included those verses then there would be calls of collusion between the authors.

But by all means let's look at those arguments.

 

[Swammerdami]

Today I played on-line bridge and went down in a contract of Five Hearts Doubled which I should have made automatically. The stakes were zero but it was still disappointing. My cognitive powers are diminishing now, at age 75, but slowly so, and I think I am still very competent to handle SOME types of logic puzzles.

I'm less competent to evaluate evidence, but that often also reduces to simple logic. For example, Google will readily tell you that MANY famous philosophers -- not Just Christians, but also Jews and atheists -- regard the parables and sermons attributed to Jesus of Nazareth to be UNIQUE, unprecedented both in message and in eloquence. We can't be sure that it was Jesus himself who conceived and preached these verses, but SOMEBODY did, and -- since there's no earlier mention of such teachings -- most probably composed the verses during or not long before Jesus' ministry. To call this preacher a "nobody" is fatuous nonsense.

I am NOT a religious person; and I am NOT interested in studying the eloquent sayings, unprecedented or not, attributed to Jesus. The topic attracted my attention SOLELY in response to a belief -- apparently widespread, at least among a class of atheists -- that Jesus never existed at all. This seemed like an interesting controversy which presented a PUZZLE and which might be resolved with careful examination of the evidence.

And frankly the mythicists resort to elaborate contortions. For me, and for almost all professional historians, a few basic facts about Jesus are true with probability 99% or so. He did NOT work miracles; he did NOT rise from the dead; and he was NOT the only begotten son of God. We know very little about him. But we DO know:

• He was born in Galilee, probably in the town of Nazareth.
• He was baptized by John the Baptist.
• He had a brief ministry, achieving fame as a preacher OR as a healer OR as an insurrectionist OR perhaps two of the above -- we can't quite be sure.
• He was crucified by order of Pontius Pilate
• Worship of Jesus grew rapidly soon after his crucifixion, centered first in Jerusalem and led by James and Simon Peter.
• A resurrection myth developed at some point. Hypnosis or even psychedelic drugs may have played a role in this.
• The evangelist now named St. Paul was active among Gentiles, especially 40-60 AD.
• Paul's followers grew in importance compared with the Jerusalem church after 70 AD.

Occam's Razor suggests that the rapid growth of this new religion depended on a real martyr, but there are plenty of other logical arguments why the above summary is probably a close approximation to historical truth. Just as I am surprised by Americans who don't see Trump for the incompetent and corrupt brat he is, so I am surprised by intelligent people who claim the above to be severely flawed. In a recent post at IIDB we see Paul placed into the 2nd century! Do these people think Luke's author, Josephus, Hegesippus, Tacitus and whoever wrote Galatians all conspired together to invent a lie?

That's why I was happy to see this thread. In this thread, we're examining actual evidence!

I have found the Farrer Hypothesis to be most satisifying i.e The Farrer hypothesis suggests a simpler model of literary dependence, with Matthew and Luke directly relying on each other's work, in addition to Mark. No need for a unknown document 'Q' or otherwise.

My understanding is that it would be unusual for lower-class Judaeans (and especially Galileans) to speak Greek, let alone to read or write it. Thus Jesus -- or whoever delivered the Sermon on the Mount -- spoke in Aramaic. Some devoted follower would have been eager to write down his words on papyrus or parchment, and they would have recorded Jesus' Aramaic speech in Aramaic. To postulate a Greek writing years later by someone who wasn't even present for the teaching is less parsimonious.

Remember that papyrus is very fragile and parchment very expensive. We would NOT expect such a document to survive. In fact historians insist that the number of early Christian documents (e.g. fragment of Gospels) that have turned up is unusually LARGE compared with other histories from such an early date.

The early Gospels, on the other hand, were written by a more educated and bilingual person, who interviewed the Christians of Jerusalem. I don't think we can rule out that this task was done by the man named Mark(!) who is mentioned once by Paul:

9 Do your best to come to me quickly, 10 for Demas, because he loved this world, has deserted me and has gone to Thessalonica. Crescens has gone to Galatia, and Titus to Dalmatia. 11 Only Luke is with me. Get Mark and bring him with you, because he is helpful to me in my ministry. 12 I sent Tychicus to Ephesus. 13 When you come, bring the cloak that I left with Carpus at Troas, and my scrolls, especially the parchments.

This Mark, and his visit to Paul, is also mentioned in Acts 12. But by Acts 15, Paul has lost interest in Mark. (Why? Because his beliefs follow those of Peter and James rather than Paul's?)

35 But Paul and Barnabas remained in Antioch, where they and many others taught and preached the word of the Lord. 36 Some time later Paul said to Barnabas, “Let us go back and visit the believers in all the towns where we preached the word of the Lord and see how they are doing.” 37 Barnabas wanted to take John, also called Mark, with them, 38 but Paul did not think it wise to take him, because he had deserted them in Pamphylia and had not continued with them in the work. 39 They had such a sharp disagreement that they parted company. Barnabas took Mark and sailed for Cyprus,

Even with no specific evidence, the existence of prior sources seems most parsimonious. Matthew and Luke were supposedly written 50+ years after the Crucifixion -- that's a long time for detailed narratives to survive in purely oral form. ...
But there is specific evidence for a written Aramaic source used independently by both Matthew and Luke. Compare Luke 11:39-41 with Matthew 23:26. Neither could have borrowed from the other. Instead Matthew correctly translated Aramaic 'dakkau' (to cleanse), while Luke misread the original as 'zakkau' (to give alms).

The discrepancy, and the fact that Luke's version makes little sense, seem like strong evidence that the authors of Matthew and Luke translated an Aramaic source independently of each other. Still it would be nice to see how 'dakkau' and 'zakkau' are rendered in written Aramaic. Is the mistaken reading likely?

 

[Tharmas]

But by all means let's look at those arguments.

I have a long answer written out but I have to format it, which may take me a little time.

 

[Tharmas]

I’m sorry to be so long getting back here, but real life intervened. So what I’ll do today is give a brief outline of the arguments for the existence of Q.

My author, Burton Mack, whom I referenced in the OP, devotes more than a chapter to the nature and history of Q arguments, and I won’t try to summarize it all here. Instead I will reference an easily accessible web page maintained by one Stephen C Carlson, who Google tells me is an associate professor of Biblical studies at the Catholic University of Australia.

The existence of Q is theorized as a consequence of the Tw0-Source Hypothesis (2SH). Carlson summarizes the argument in a nutshell:

Mark was a source for Matthew and Luke, both of whom also independently used a now lost sayings source called Q.

There are two lynchpins to the 2HS. The first is the primacy of Mark, that is, Mark was the first of the synoptic gospels to be written and Mathew and Luke used it as a source. The second deals with the fact that both Matthew and Luke contain material that is quite similar if not identical, but that is not found in Mark. It is hypothesized that this material, consisting largely of Jesus’ sayings and parables, was found in a second source, now lost, which Matthew and Luke independently made use of.

I will now expand on these two lynchpins.

Lynchpin One: The Primacy of Mark

Carlson identifies two main classes of argument:

1. Arguments from Content

2. Arguments from Wording

Arguments from Content

Quoting Carlson:

It is argued that it is easier to understand certain material (infancy accounts, Sermon on the Mount) being added to Mark by Matthew and Luke than the reverse of Mark's omitting them from Matthew and Luke. It is also argued that it is easier to view Matthew's and Luke's relative brevity in the account all three share as both Matthew's and Luke's compressing the text of Mark to add their own material rather than Mark's abridging the content and expanding the words of one or both of the others. Furthermore, critics have argued put forth reasons for the specific divergences of Matthew's and Luke's order of their material from that of Mark's as more plausible than the reverse. (Stein 1987: 48-51; Tuckett 1992: 264-265)

Arguments from Wording

Again quoting Carlson:

At a general level, proponents of Markan priority find Mark's less literary diction, grammar, redundancy, difficulty of expression, Christology, and use of Aramaic to more likely be intentional improvements by Matthew and Luke rather than Mark's "dumbing down" of one or both of the others (Stein 1987:52-67; Tuckett 1992: 265-267). On a more specific level, Markan priority is also found to in instances where Matthew and Luke seem to occasionally refer to omitted explanatory material in Mark, in Matthew's adding his own theological emphases rather in than Mark's removing them, and an uneven distribution of Mark's stylistic features in Matthew. (Stein 1987: 70-83)

(Incidentally, Carlson references your guy Farrer as a “notable” theorist who accepts the priority of Mark but disparages the existence of Q.)

Lynchpin Two: The Existence of Q

Carlson’s brief summary:

The existence of Q follows from the conclusion that Luke and Matthew are independent … Therefore, the lite[r]ary connection … must be explained by an indirect relationship, namely, through use of a common source or sources.

Again, Carlson identifies two main classes of arguments:

1. Arguments from Content and Argument

2. Arguments from Wording

Arguments from Content and Argument

The assumption that Luke did not use Matthew as a source, and vice-versa, is indicated by the fact neither copies the other’s non-Markan, non-sayings (Q) material. Furthermore, apparently “neither knew the other's arrangement of the non-Markan material with respect to the Markan outline.”

Arguments from Wording

The Q hypothesis is used to explain why the form of the material sometimes appears more primitive in Matthew but other times more primitive in Luke in the face of very impressive exactness in wording in other parts … (e.g. Matt 6:24 = Luke 16:13 for 27 of 28 Greek words and Matt 7:7-8 = Luke 11:9-10 for 24 of 24 Greek words).

One final note, which Carlson doesn’t mention, is that the discovery of The Gospel of Thomas in 1945 proves that “sayings” gospels, as proposed by the Q theory, were a real thing, although so far only Thomas has been discovered.

So those are the bare bones of the Q argument. I have eliminated references to “the double tradition” and “the triple tradition” that Carlson incorporates as I didn’t see that they added clarity to the discussion.

 

[Tharmas]

My understanding is that it would be unusual for lower-class Judaeans (and especially Galileans) to speak Greek, let alone to read or write it. Thus Jesus -- or whoever delivered the Sermon on the Mount -- spoke in Aramaic.

Burton Mack paints a picture of Galilee as a multi-cultural international crossroads. In such an environment it would not be surprising to find many Aramaic speakers to be somewhat conversant in Greek, even if they were not fluid speakers. It is recognized that there is a good deal of Aramaic influence in Mark's text. In some cases Mark provides the Aramaic phrase and then translates it, presumably for the benefit of his Greek readers. Combine this with the fact that, as Carlson notes above, Mark's Greek is somewhat primitive compared to Luke's and Matthew's, we can speculate that Mark 's first language was Aramaic. That's simply my speculation, but there are some scholars who might agree with me.

From Google AI (search terms "The Gospel of Mark" and "Aramaic"): "Some theories propose that Mark, or parts of it, might have been originally written in Aramaic or that the author relied on earlier Aramaic narratives or oral traditions."

 

[Swammerdami]

... Much of the synoptic Gospels came from a common source ("proto-Mark"(?)) Is it clear which of the three is closest to the common source? Shouldn't it be possible to guess which is closest by careful reading?

For example, in the story of the swine drowning in a lake the spirit names itself "Legion" but not in Matthew. Did Matthew delete this detail from the common source, or did the other two Gospels add it? Similarly Matthew places the incident in the region of the Gadarenes, while the other two place it in the region of the Gerasenes....

I Googled to understand that Gerasa and Gadara are cities (55 km apart) in Decapolis, with Gerasa midway between Gadara and Philadelphia (Amman) and Gadara midway between Gerasa and Nazareth.

The Decapolis ('Ten Cities') was a group of ten Greek Hellenistic cities on the eastern frontier of the Greek and late Roman Empire in the Southern Levant in the first centuries BC and AD. Most of the cities were located to the east of the Jordan Rift Valley, between Judaea, Iturea, Nabataea, and Syria. The Decapolis was a center of Hellenistic culture in a region which was otherwise populated by Jews, Arab Nabataeans and Arameans.

This page discusses the relevant geography, and mentions that Eusebius introduced a third possibility: the village of Kursi/Gergesa. This village is too small to be one of the Ten Cities, but is near Hippus, itself one of the Ten Cities of Decapolis. This makes more sense if the swine raced into Lake Tiberias (Sea of Galilee) since, as another webpage states

“Gergesenes” is also in some [Mark/Luke?] manuscripts (Khersa or Gersa was a town actually on the shore of the sea).

Confusion arose in part because Gospel writers wanted to give their readers, unfamiliar with geographic details, a recognizable city name.

... All of which reminds me that the whole topic is a HUGE "rabbit-hole" down which countless scholars have been exploring for centuries; and I lack the time or expertise to fathom. Two conclusions:

(1) That Jesus and disciples visited Hellenistic Decapolis supports Tharmas' claim that some disciples were likely conversant or even bilingual in Greek.

(2) The Gadarenes/Gerasenes discrepancy suggests to me that Matthew and Mark/Luke were working from the account of a fourth writer and/or were all familiar with the relevant Decapolis geography. (Or was Matthew FIRST, and Gadarenes an error that Mark/Luke knew to correct?)

But the main conclusion for me is "Stay away from such vast rabbit-holes"!