That said, I'm not sure I'd attack it from the angle of how many peasants from Galilee knew Greek (well enough.) While the percentage is likely extremely low in the rural areas, it's really only relevant if someone claims that, say, the epistles of Peter, John, and so on, are written by exactly those apostles. Then it is probably relevant to estimate: if you took 12 more or less random fishermen and other lower class, for no other reason or qualification than being there when Jesus goes "ok, you guys leave everything and come with me", what's the chance that even one of them would not only know how to write, but also be fluent in Greek and skilled in literary devices and sophistry?
Unfortunately, we're a century or two for that to still be relevant. Nowadays even religious scholars are aware that Peter's epistles weren't written by Peter, and in fact they can't even be both written by the same person. Or pretty much everyone agrees that the gospels of Mark, Matthew, Luke and John aren't written by the Mark, Matthew, Luke or John that the church tradition ascribed them to. (Although knowing that they're not written by Mark or Matthew doesn't stop some people from trying to equivocate those with the different Mark and Matthew mentioned by Papias anyway.)
What is still contested isn't whether any of those wrote their respective stuff, or even if they knew Greek or Latin at all, but whether there still is a reliable chain of information anyway. And that's pretty hard to attack purely from the angle of what language would Peter speak, since it only takes a translator for that to stop being a problem. In fact, it's so obvious that it occured to people in the very early 2nd century CE: that's what got us the invention of Mark as the personal translator and secretary or Peter.
Seriously, it's like the God of the gaps all over again. From the original claim that that stuff is written by literal eye-witnesses and best buddies of Jesus, or, as the case may be direct associates of Peter or Paul, when that got untenable, now it's been dropped down a notch to just claiming that, basically, "yeah, ok, so it may have been written 60 years after the fact, by people who never even saw the region or knew anything, but it's still reliable because THEY HAD WITNESSES." The BS support handwaved is that the place was teeming with all sorts of eye witnesses of all those miracles, and even hostile witnesses (e.g., from the Pharisees) who would have corrected any mistake. That you couldn't have made up any detail, no matter how small, without a bunch of people going "no, that's not how it happened!" at you. And that of course, those writing the fanfics... err... gospels would, of course, correct the text to such a degree that verily none of those gazillions of witnesses found anything to object.
Which I guess is a good setup for illustrating what I mean by actually using Bayes instead of just trying to handwave through a base rate fallacy. Before I get started, if anyone somehow missed what Bayes is about... well, I'm too lazy to type it all, but just so we're on the same page about the variables and formula, I'll just copy this from
Richard Carrier's pdf. Or you can get it off wikipedia, or whatever.
P(h|e.b) = P(h|b) x P(e|h.b) / [ P(h|b) x P(e|h.b) + P(~h|b) x P(e|~h.b) ]
Where:
P = Probability (epistemic probability = the probability that something stated is true)
h = hypothesis being tested
~h = all other hypotheses that could explain the same evidence (if h is false)
e = all the evidence directly relevant to the truth of h (e includes both what is observed
and what is not observed)
b = total background knowledge (all available personal and human knowledge about
anything and everything, from physics to history)
P(h|e.b) = the probability that a hypothesis (h) is true given all the available evidence (e)
and all our background knowledge (b)
P(h|b) = the prior probability that h is true = the probability that our hypothesis would
be true given only our background knowledge (i.e. if we knew nothing about e)
P(e|h.b) = the consequent probability of the evidence (given h and b) = the probability
that all the evidence we have would exist (or something comparable to it would
exist) if the hypothesis (and background knowledge) is true.
P(~h|b) = 1 – P(h|b) = the prior probability that h is false = the sum of the prior
probabilities of all alternative explanations of the same evidence (e.g. if there is
only one viable alternative, this means the prior probability of all other theories is
vanishingly small, i.e. substantially less than 1%, so that P(~h|b) is the prior
probability of the one viable competing hypothesis; if there are many viable
competing hypotheses, they can be subsumed under one group category (~h), or
treated independently by expanding the equation, e.g. for three competing
hypotheses [ P(h|b) x P(e|h.b) ] + [ P(~h|b) x P(e|~h.b) ] becomes [ P(h1|b) x P(e|
h1.b) ] + [ P(h2|b) x P(e|h2.b) + [ P(h3|b) x P(e|h3.b) ])
P(e|~h.b) = the consequent probability of the evidence if b is true but h is false = the
probability that all the evidence we have would exist (or something comparable to
it would exist) if the hypothesis we are testing is false, but all our background
knowledge is still true. This also equals the posterior probability of the evidence if
some hypothesis other than h is true—and if there is more than one viable
contender, you can include each competing hypothesis independently (per above)
or subsume them all under one group category (~h).
Now let's say that:
- our evidence
e are the episodes in Matthew where the Sun has a 3-hours long eclipse on a full moon, and there's a 3-day long plague of zombies in Jerusalem, and the slaughter of innocents, and so on. You know, all the enormities in there.
- our hypothesis
h is that our friend Matthew did indeed have access to enough reliable and impartial eye-witnesses, and actually would cross-check every event with them, and correct his version if the witnesses say it ain't so.
I reckon, he needs some 3-4 witnesses to even cover all that happened in Jerusalem, because any less and someone wouldn't be on scene for one or the other of them. I mean, according to the Bible, even the apostles themselves weren't witnesses to everything Jesus did or everything happening at the trial (they wouldn't be sent with Jesus to Caiaphas and Herod and so on) and so on.
- our body of evidence
b is all we know on the topic, including that it's biological and physical impossibilities, and more importantly that a lot of people would have had good reason to write about those events (e.g., for an astronomer at the time, that eclipse would have been THE most significant event ever) and yet none of them did.
- P(h|b) is basically, what are the odds that Matthew would have such witnesses and actually be meticulous about cross-checking every single claim, if we didn't know anything about the evidence, i.e., what he's writing about. Usually this one is handwaved implicitly as the one number that matters, presumably because it can be argued to a lot higher than the rest.
Actually that's fairly low anyway, because in that age, everyone made up public speeches and such. And generally people didn't check even flat out claims that someone was born of a god. Or apparently in Apollonius of Tyana's case, his mom made him with TWO gods. (Holy gangbang, batman!
) Plus, resurrections, raising the dead, public miracles, etc. People didn't exactly have the requirement to have two corroborating witnesses at the time.
Plus by the time of Matthew we're getting past the median life expectancy at the time. Someone who was, say, a couple of years old at the time of the crucifixion, to be over the immense infant mortality spike already, would already have over 50% chances to be dead. But you wouldn't trust the memories of a 3 year old at the time, so, really, you'll want someone who was at least an adult at all at the time, i.e., 13 years old. Which is already on the tail end of the curve.
So not only checking with several witnesses wasn't a given at the time, even HAVING those eyewitnesses around that cover enough of Jesus's ministry in one place is going to be a problem.
So let's say... one in ten? Though as we'll see, it won't make much of a difference even if I start with a prior of 50-50, so I'll actually go with 50-50. Which is the general "I don't know" kind of prior.
- P(e|h.b) is the probability that we'd actually have that evidence
e, or something similar, if our background knoweldge is correct AND the hypothesis is correct. What are the odds that a Matthew who scrupulously checked it with several reliable eye-witnesses, and actually corrected the manuscript if the witnesses disagreed, would end up writing about a 3-hour solar eclipse on a full moon and a zombie invasion that spans several days?
Well, now that one ain't very likely, is it? Basically the only ways to reconcile both requirements is one or both of the following:
A) all witnesses Matthew has access to are nuts. Schizophrenia being about 1%, for even 3 witnesses to be schizophrenic, we have a 1 in a MILLION chance. Of course, back then it was higher without medication, and we are talking some old people too, but by the time you get to 4 witnesses, it kinda compensates for that.
B) the solar eclipse and zombie invasion DID happen, but all those people who had good reasons to be interested in such events, somehow forgot to write about the most significant event in their profession EVER. Well, that ain't very likely either. If every astronomer at the time had just 1 chance in 10 to just omit writing about the most significant astronomical event ever (which is a very generous chance, much higher than is realistic to expect) then you only need 6 of them to have 1 in a million odds, and a dozen of them give you a 1 in a TRILLION chance of it happening. We actually have more than a dozen, IIRC.
When we add the other stuff in there that nobody wrote anything about, well, let's just say it's multiplied not added, so the chance of all that stuff happening in major cities and nobody ever writing about it is truly insignificant.
So let's go with just the 1 in 1,000,000 chance that Matthew is carefully crosschecking it with a bunch of witnesses... who are thoroughly insane.
- P(~h|b) is 1-P(h|b). Since I said I'd go with a ludicriously gullible 0.5 as the prior P(h|b), this one is 0.5 too. Which makes the maths a lot easier, since we can just reduce the 0.5 above and below the fraction line.
- P(e|~h.b) is basically what are the odds that you'd end up with such ridiculous miracle stories if Matthew ISN'T checking it with a bunch of reliable witnesses, including the case that he's not checking it with anyone at all.
Well, let's say 1 in 10, basically allowing that 90% of those writing successful religious propaganda, aren't making up anything TOO extraordinary. I'm being way generous there, but let's go with that.
So basically we have our probability that the hypothesis is true be
0.5 x 0.000001 / [ 0.5 * 0.000001 + 0.5 * 0.1 ] = 0.000001 / [ 0.000001 + 0.1 ] = 0.000001 / 0.1 = 1 in 100,000
(Given that we don't have any real accuracy beyond the order of magnitude, 0.000001 + 0.1 is pretty much just 0.1)
So basically really, the chance that G.Matthew is actually cross-checking his story against eye-witnesses, are 1 in 100,000 or less. Actually with some more realistic numbers, it would be a lot less.
And basically, really, that's how one argues "probably" with Bayes.
