However, most religious movements clearly have human founders (e.g. Joseph Smith or Muhammad),
Or Pythagoras or Haile Selassie (see e.g., the attached, Standing, E. (2010). Against mythicism: A case for the plausibility of a historical Jesus. Think, 9(24), 13-27.)
and the assumption here is not that a founder existed, but that Jesus Christ, its object of worship, existed historically and was the founder.
True. That is indeed part of the assumption. However, as "Christ" was so loaded a term that the Greek hardly touches upon it and given the matrix from which the gospels (let alone the letters of Paul) originated, one is hard pressed to dream up some explanation for Christianity without Jesus, providing one is aware of historical methods and the context(s) relevant here.
Standing's paper is a straw man argument that Jesus probably existed because we can cite examples of real people who became the basis for a legend. It is easy to counter that with examples of cult leaders who probably never existed but became the object of cults. Just because
John Frum is said to have spawned the Cargo Cult religions, that doesn't mean that there was a real person named "John Frum" who spawned them. Maybe there was a real Robin Hood or King Arthur, maybe not.
Was there a real person whose existence led to the
Santa Claus legend? Well...sort of. There was
Nikolaos of Myra. But do we therefore claim that there was a historical Santa Claus? No, not really. That's not what the historicism/mythicism debate is about. Historicists are not talking about just someone who happened to be crucified and then had all sorts of nonsense made up about his life. They are talking about someone who had a fair number of attributes that we attribute to Jesus--a religious leader who inspired a following.
...Mark is generally dated fairly close to Paul. Josephus, Paul, and Q all refer to Jesus' brother. Tacitus tells us that while Paul lived the Christians were named for their founder Christ and were generally hated (a sentiment echoed in Pliny and Suetonius).
But what can the expression "fairly close" mean? We do not have the autograph, and what we have is basically a reconstruction of what scholars believe was the original text. So there is a lot of debate and speculation about dating. The other two synoptic gospels clearly use it as a reference source, but we have no original sources for any of the four gospels. Jesus was a very popular cult figure in the second century, so there were a lot of stories about his life circulating in the Empire. Most of them were suppressed by the later orthodox movement, because they conflicted with official church doctrine. I don't see the gospels as a credible basis for promoting historicism. Only Paul is thought to have been a contemporary of Jesus, but much of what he wrote was not preserved, and forgery of religious materials was rampant in the Empire. So scholars only treat some of the writings attributed to Paul as having been authored by him. And he did seem to suffer from delusions, given the content of what we do trust him to have written. Did he meet the brother of Jesus? Was he using the word "brother" in a religious sense (as Richard Carrier has claimed)? Was it just in his imagination, as were other things he said? Was he lying? There are many possibilities.
The NT itself seems to have appeared only in the 2nd century
The oldest of the gospels, that of John, is ironically the earliest text for which any manuscript evidence exists, in that the earlier fragment of the NT dates from the first half of the 2nd century and is a portion of John. Given the location of its finding and the fact that it is almost universally agreed to be the latest, for the "NT itself" to "have appeared only in the 2nd century" is not even supported by actual manuscript evidence. The historical evidence, from Marcion to Papias, simply makes such a reading more utterly implausible.
Pay attention to what I wrote. The NT is an anthology. Irenaeus may not have been the first to promote the anthology, but he is our earliest attestation of the existence of the "fourfold gospel". Each piece would obviously have existed independently before Irenaeus, but so did other Jesus stories. Christianity was a much more diverse community in the second century than it was allowed to remain after the fourth, when orthodoxy rose up on its hind legs and smote all its competitors.
, when Irenaeus promoted his "fourfold" Gospels as the only authentic accounts in reaction to the competing Gnostic tradition.
This is quite simply incorrect, even were it not for the fact that whatever the "gnostic tradition" was it was clearly so diverse as to be connected only because of modern scholarship.
No, it's not incorrect according to what I've read. See, for example, the Wikipedia article on Irenaeus, which primarily references Will Durant's book
Caesar and Christ (1972):
Wikipedia said:
Irenaeus' best-known book, Adversus Haereses or Against Heresies (c. 180), is a detailed attack on Gnosticism, which was then a serious threat to the Church, and especially on the system of the Gnostic Valentinus. As one of the first great Christian theologians, he emphasized the traditional elements in the Church, especially the episcopate, Scripture, and tradition. Against the Gnostics, who said that they possessed a secret oral tradition from Jesus himself, Irenaeus maintained that the bishops in different cities are known as far back as the Apostles and that the bishops provided the only safe guide to the interpretation of Scripture. His writings, with those of Clement and Ignatius, are taken as among the earliest signs of the developing doctrine of the primacy of the Roman see. Irenaeus is the earliest witness to recognition of the canonical character of all four gospels.
There is no independent evidence to corroborate his position, and the textual record clearly contains a great many myths and forgeries interspersed with details that could possibly be believable.
What do you mean by "textual record"?
Written materials from the period of the Roman Empire. What did you think I meant?
Upon what are you basing your view of what "biblical scholars" do?
Upon what I've read that they do. It is not an unprecedented behavior. Thomas Jefferson is famous for having reconstructed the Bible so as to remove all of the references to miracles. What scholars do with the historical record is not quite as gross, but it is analogous. They do not let all of the contradictions and obvious embellishments get in the way of taking the rest of the text seriously. However, all of that discarded material ought to be a warning to those who would accept the rest as plausible. You can ignore the goofy stuff, but you ought not to ignore the fact that it is there. For those of us of a more skeptical mind, it may not poison the well, but it makes the water smell awful fishy.
So we get references from folks like Josephus, Tacitus, and Pliny the Younger, who could only report secondhand accounts and whose writings may have been contaminated by error or interpolation.
That is if we for no reason whatsoever discount Christian sources, a method seemingly adopted as necessary by all those who haven't studied or contributed to historical scholarship here, and if we dismiss the Talmud, Mara bar Serapion, Thallus, and non-canonical sources. Having done so, we still are left with a relatively incredible foundation of sources.
And an incredibly skewed one, thanks to the meddling, censorship, and outright book-burning by people who were motivated to distort the historical record for the sake of personal profit or personal bias. I have not advocated just dismissing it all out of hand, but I have advocated not accepting it out of hand. What mainly bothers me is all of that non-existent material that one would expect to be there or that we only possess fragments of to sift through. Given the importance of the Jesus figure to its followers, one would expect them to have preserved more than just scraps of text. Instead, they fought with each other over who got to say anything at all about Jesus. Scholarship got pushed aside by doctrine. So don't be so quick to dismiss mythicism out of hand.
Lots of folks told stories back then
Yet there exists no parallel to the gospels excepting their classification as ancient biographies.
I'm really not sure what you are talking about here. The gospels are hagiographies, not real biographies. And there were other works of that genre back then.