Monday, July 22, 2013

Proving History?

So I finished reading Richard Carrier's book "Proving History: Bayes's Theorem and the Quest for the Historical Jesus" which I mentioned in the previous post.

A few things to say about Richard Carrier before I make comments on this book in particular:
  1. Carrier is an intelligent guy who thinks things through in greater detail than many people do.
  2. He also comes across as quite arrogant in interviews and in some of the things he writes.
  3. His logic appears to be sound and his conclusions generally appear to be justifiable.
  4. He has a clear idea of who his audience is, and tailors his writings to that specific audience.
Starting with that final point, I don't think I am the audience Carrier is writing to in this book. In many of the books by 'new atheists' which I have read, I've realised that the authors are generally 'preaching to the deconverted', as it were, and are not realistically expecting many believers to be reading their books. 'New atheism' books are aimed to give ammunition to atheists. Of course, the flipside of that is that most apologetics books are aimed at Christians to reinforce their beliefs, and not to try to convince atheists to believe...

So, point number one in this review, I don't think any Christian is going to be swayed by the arguments made in this book, even if they (the arguments, that is) are logical, justified and, indeed, correct. But, of course, this book doesn't really set out to sway anyone with its conclusions about history, the main point of this book is to demonstrate to its (mostly non-mathematically inclined) audience that the mathematical technique of Bayes's Theorem is appropriate in historical investigation, and furthermore is the best method to use in historical investigation. I think the book manages to do that, but as conclusions go, its not a very exciting one. The much more exciting and dramatic conclusion comes in Carrier's next book, which isn't out yet.

As a side note, I'm glad that Carrier settled on consistent use of "Bayes's Theorem" rather than "Bayes Theorem", which I find acceptable, or "Bayes' Theorem", which is clearly not acceptable to anyone who understands grammar. Of course, he abbreviates it to "BT" for most of the book, which gets around the problem of the apostrophe. But anyway...

On the whole, this is not a very interesting book. It has interesting bits in it, and makes some interesting conclusions along the way, but I can't really recommend this to anyone as a good read. I doubt even Carrier thinks this book is particularly interesting, but it probably is required before we get to the meaty stuff in the next book. And therein lies the problem, this is clearly the build up to the much more interesting work which is to follow, and may be required reading to understand that second work, but by itself this is a bit dry.

I guess I should explain what Bayes's Theorem is. Put simply, it is a mathematical method for updating your beliefs in the light of new evidence. As used by Carrier, it is a method of assessing the probability of one or more historical hypotheses by considering one or more pieces of evidence. The method provides a framework for determining whether our confidence in a given belief (hypothesis) should be increased or decreased as new evidence presents itself. (I should note here that I have used Bayes's Theorem in my work for over a decade now, so I am fairly familiar with it, and thus am far from the target audience of this book.)

The point of this book is to convince the reader (who Carrier expects to be a non-mathematically inclined person with an interest in history) that Bayes's Theorem is a sound and justifiable method for coming to historical conclusions. He wants everyone to share this belief. If he gets everyone to share this belief, then everyone will have to accept any historical deduction he makes using Bayes's Theorem. And in the next book (I expect) he will end up using Bayes's Theorem to show that Jesus was not the Son of God and, furthermore, probably didn't exist. But in order for that argument to work, he has to get you to accept the method.

The fundamental problem in this kind of reasoning is this, that faced with an anti-Christian conclusion derived using Bayes's Theorem, the non-mathematically inclined Christian historian who accepted BT on the basis of this book will reject it again after the next book, because their acceptance of the truth of Christianity is so much stronger than their acceptance of the truth of Bayes, that the only conclusion they can come to is that Bayes's Theorem must be flawed, even if in some way that is not immediately apparent. So I fear that the end result of this will be an insufferably smug Richard Carrier, who knows - beyond reasonable doubt - that he has proved that Jesus didn't exist, and a bunch of Christians who have read this, who know that Carrier must be wrong.

But Carrier does an excellent job of demonstrating that Bayes's Theorem is a valid way of estimating historical probability, and a pretty good job of demonstrating that it is the best method of estimating historical probability.

Perhaps the most interesting chapter in the book is Chapter 5, where he looks at the various criteria used by historians involved in the 'quest' for the 'Historical Jesus' and either demonstrates that each criterion reduces to Bayes's Theorem, or is invalid as a method. Thus the point is proved, Bayes's Theorem is the fundamental valid method underlying all other historicity criteria.

Taken one by one:
  1. Dissimilarity: demonstrated to be invalid.
  2. Embarrassment: similarly invalid. Carrier deconstructs this one at great length, indeed, it is the largest part of the chapter by far. Along the way, he makes a very interesting statement that I must investigate further sometime:
    "Its worth remarking here, ..., that everyone literate enough to compose books in antiquity was educated almost exclusively in the specific skill of persuasion: that is what all writing was believed to be for, and how all literate persons were taught to write." (page 134)
    Thus, everything in an ancient book was there for the purpose of convincing the reader of something, so nothing embarrassing which hindered this purpose would be included.
  3. Coherence: shown to be invalid.
  4. Multiple attestation: shown to be invalid.
  5. Explanatory credibility: consistent with Bayes, but can only exclude, never confirm.
  6. Contextual plausibility: similarly consistent with Bayes.
  7. Historical plausibility: again, consistent with Bayes, but is incomplete.
  8. Natural probability: consistent with Bayes, but doesn't make as strong a case as could be formulated with Bayes, so Bayes supersedes this method. 
  9. Oral preservability: consistent with Bayes, but can only exclude.
  10. Crucifixion (the theory has to explain why Jesus was deemed worthy of crucifixion): not valid.
  11. Fabricatory trend: consistent with Bayes, but can only exclude.
  12. Least distinctiveness: of limited use, but consistent with Bayes.
  13. Vividness of narration: shown to be invalid.
  14. Textual variance: invalid.
  15. Greek context: invalid.
  16. Aramaic context: invalid.
  17. Discourse features: invalid.
  18. Characteristic Jesus: invalid, as it relies on many of the above invalid methods.
Wow. I hadn't realised there were so many rubbish criteria in use by Historical Jesus scholars. Carrier shows that most of them are useless and the rest of them are poor-man's versions of Bayes, so to use Bayes directly is better than using any of them.

Anyway, I think I've said all I need to here. There's an interesting Jesus vs Daniel thing that I'll maybe pick up in a future post, but I'll not go into it here.

In summary, I agree with Carrier's conclusion: "Historians should be Bayesians". We'll see what happens when Bayes is applied directly to Jesus in the next book by Carrier.


13 comments:

Fortigurn said...

"Thus the point is proved, Bayes's Theorem is the fundamental valid method underlying all other historicity criteria."

The fact that you follow Carrier's error of wrongly describing the criteria of AUTHENTICITY as criteria of HISTORICITY, shows you (like he), needs to read more on the subject. I suggest you start with a basic primer on the quest for the historical Jesus, so you actually know what you're talking about first.

Ricky Carvel said...

Hi. I have read quite a bit on the quest for the historical Jesus, but I don't see that that's entirely the point here.

The question is a question of history, not merely a question of historical-Jesus-history, so Carrier could know nothing whatsoever about the quest and still show that Bayes is the best method of assessing historical probability.

And besides, I don't even mention a criterion of authenticity.

Ignorance said...

"And besides, I don't even mention a criterion of authenticity."

That is Fortigurn's point: these "historicity criteria" are actually criteria of authenticity. So they do not demonstrate historicity, but neither do they intend to.

Fortigurn said...

That is exactly the point.

Fortigurn said...

Let me explain in detail where you have gone wrong, starting with this comment of yours.

"Perhaps the most interesting chapter in the book is Chapter 5, where he looks at the various criteria used by historians involved in the 'quest' for the 'Historical Jesus' and either demonstrates that each criterion reduces to Bayes's Theorem, or is invalid as a method. Thus the point is proved, Bayes's Theorem is the fundamental valid method underlying all other historicity criteria."

Here you talk about "various criteria used by historians involved in the 'quest' for the 'Historical Jesus'", and you refer to them as 'historicity criteria'.

You make two mistakes. Firstly, these are not criteria used by HISTORIANS, they are criteria used by NEW TESTAMENT SCHOLARS.

Secondly, they are not historicity criteria, they are criteria of AUTHENTICITY. The criteria of historicity are different, and are used by professional historians. You pointed to the criteria of AUTHENTICITY, and wrongly referred to them as criteria of HISTORICITY.

Finally, it clearly needs to be said here that the search for the historical Jesus is NOT an investigation of the historicity of Jesus. It is not a quest for the HISTORICITY of Jesus.

Ricky Carvel said...

Ah. I think I see where you're coming from now. What you're taking to task is not Carrier's use of Bayes's Theorem, rather you're taking the entire methodology of the 'quest' to task!

So, fundamentally, you are agreeing with Carrier when he demonstrates that the various criteria are misapplied or are invalid.

I agree that most of the 'scholars' involved in the 'quest' are not historians, but are NT scholars. Sorry, I clumsily confused the two categories in my original review.

But I think my original conclusion still stands. Bayes's Theorem is neither a historicity criterion nor an authenticity criterion, it is a robust and justifiable methodology for assessing the probability of a hypothesis, given appropriate evidence. Thus it could be applied to hypotheses about historicity as much as it could be applied to hypotheses about authenticity.

You seem to be suggesting that the questors are using a fundamentally flawed methodology. This may be the case, and is part of what Carrier is trying to prove.

Personally, I am suspicious about the 'quest' because it seems to me to presuppose two historical claims: firstly, that there actually was a historical human Jesus, and secondly that this historical character is significantly different from the character described in the Bible. Those two 'facts' seem to be a given for all involved in the quest, so the traditional Christian belief and the 'Christ myth' hypothesis are disregarded at the outset.

Carrier, who I think is a historian, not an NT scholar, is attempting to devise a methodology which is free from such a bias.

If you believe Bayes's Theorem doesn't work as this, then please explain why.

Ricky Carvel said...

By the way, my dictionary defines "historicity" as "historical authenticity" so I'm still struggling to care too much about the distinction between the two words. If something is shown to be inauthentic, then it is also unhistorical; if something is shown to be unhistorical, is it not also inauthentic. So why bother with the distinction?

Fortigurn said...

No I am not taking the entire methodology of the quest to task. I am explaining that not only do you fail to understand the aim of the quest, you fail to understand the aim of the criteria, and you even completely mis-name them. Let me break it down.

1. The aim of the Jesus quest is NOT to prove the historicity of Jesus. That is the work of professional historians.

2. The aim of the Jesus quest is to reach a conclusion on WHO Jesus was, and WHAT his aims were. The historicity of Jesus is not questioned by the Jesus quest, because the historicity of Jesus has already been established and accepted by the scholarly consensus of PROFESSIONAL HISTORIANS. New Testament scholars are in no position to dispute such a scholarly consensus, and there is no reason for them to do so. New Testament scholars SHOULD accept the historicity of Jesus as established by professional historians, just as philosophers accept the historicity of Socrates and Plato as established by professional historians.

3. The criteria you listed and wrongly referred to as criteria of HISTORICITY, are not criteria of historicity. They are criteria of AUTHENTICITY.

4. It is NOT the aim of these criteria to establish the historicity of Jesus. That is not what the criteria were created for. You keep treating them as if they were created to establish the historicity of Jesus; they were not. You do not understand what they were created for.

5. They were created to assess the authenticity of the JESUS TRADITION, namely the texts and ur-texts of the earliest Christian movement. That is why they are called criteria of AUTHENTICITY. They were not created to assess the HISTORICITY OF JESUS.

6. The criteria of authenticity assess the AUTHENTICITY of the Jesus tradition, consisting almost entirely of the gospels, Acts, and the letters and epistle.

7. That is, they assess the PROBABILITY of sayings and events recorded in the Jesus tradition, as AUTHENTIC; what Jesus really said or did.

8. Because they are SOMETIMES used to assess the probability of EVENTS in the life of Jesus, they are SOMETIMES referred to (though uncommonly), as criteria of historicity. However, this usage is very rare; over 90% of the time they are referred to as criteria of AUTHENTICITY. But even when the term 'criteria of historicity' is used, the term does not mean 'historicity of JESUS'; it means 'historicity of the EVENT' under examination.

9. What you are doing is like this.

You: These are criteria for wine testing; number of seats, fuel consumption, percentage of recyclable materials, top speed, total cost of ownership, warranty. These criteria are clearly useless for testing wine!

Wine tester: Actually those aren't criteria for testing wine at all, you've just listed criteria for assessing a family car. When we test wine, we use completely different criteria.

You: So you're saying the entire methodology of wine testing is flawed! I knew it!

Wine tester: No, I'm saying you don't understand which criteria we actually use to test wine, and you've listed criteria which are used for a completely different purpose.

Now a few more points.

"Personally, I am suspicious about the 'quest' because it seems to me to presuppose two historical claims: firstly, that there actually was a historical human Jesus, and secondly that this historical character is significantly different from the character described in the Bible."

I've already addressed the first. As for the second, I see no evidence for it.

"Carrier, who I think is a historian, not an NT scholar, is attempting to devise a methodology which is free from such a bias."

Carrier is an unemployed PhD graduate who has never held a professional position or academic post. He doesn't even understand the criteria he's criticizing.

"If you believe Bayes's Theorem doesn't work as this, then please explain why."

I am not making any comment on the use of Bayes' Theorem as it applies to historiography.

Fortigurn said...

"By the way, my dictionary defines "historicity" as "historical authenticity" so I'm still struggling to care too much about the distinction between the two words."

Let me explain the root of your confusion; authenticity != historicity. If we look at a collection of manuscripts of the Illiad, we need to apply criteria of authenticity to determine which parts of the text were actually written by Virgil and which were not; which parts are AUTHENTIC and which are not. This does not tell us anything about the HISTORICITY OF WHAT THE TEXT DESCRIBES. It does not tell us anything about the HISTORICITY of the events described in the Illiad. It is completely separate to the issue of historicity.

When New Testament scholars apply criteria of AUTHENTICITY, they are doing what textual critics and other scholars already do with all other ancient texts; they apply criteria of AUTHENTICITY to determine which parts of the text are an AUTHENTIC REPRESENTATION of the original writer and the events described. This has nothing to do with whether or not the events described are historical.

"If something is shown to be inauthentic, then it is also unhistorical; if something is shown to be unhistorical, is it not also inauthentic. So why bother with the distinction?"

Suppose we find in Tacitus' Annals, a description of an event which took place long after the death of Tacitus. We know for a fact that this is not AUTHENTIC; our criteria of authenticity tell us that any text in Annals describing events after the life of Tacitus cannot be authentic. But although the passage is INAUTHENTIC, the event it describes may still be HISTORICAL; it may be a genuine historical event which has been added by a later scribe, to the original text of Tacitus. In fact we have a number of examples of such interpolations in ancient writings. So proving something is INAUTHENTIC does not mean it is necessarily also UNHISTORICAL.

Ricky Carvel said...

OK. I accept that a real, 'historical' event or person could leave no 'authentic' evidence. So proving that any writing is authentic or inauthentic does nothing to prove or disprove the historicity of that event or person.

But if some or all of the only tradition we have for the person or event is found to be inauthentic, then we have to question whether or not the events described actually happened, or whether the person depicted actually said those things.

So a demonstration of inauthenticity would effectively cast doubt on the historicity of the event described, unless other authentic evidence is found.

Without authenticity, you cannot demonstrate historicity.

"As for the second [that this historical character is significantly different from the character described in the Bible], I see no evidence for it."

As far as I can tell, the quest for the 'historical' Jesus presupposes that some of the pericopiae are authentic and that some are inauthentic - that is, that the stories do not go back to the historical Jesus, that is we have no way of knowing if he said or did some of the things attributed to him in the Bible stories.

So a historical character who taught in parables, was called Jesus, was crucified by the Romans, but (for example) did no miracles and was not raised from the dead, would be substantially different from the Biblical Jesus.

Even if the questors don't admit it, they are either seeking to validate everything in the Bible for apologetic ends, or they are seeking to redefine Jesus as something other than described in the Bible, usually for anti-apologetic ends.

My interest here is not as a Jesus scholar, or a historian, but rather as someone who was raised to believe in the stories of Jesus as being actual, reliable, historical events. The point of this, for me, is to ascertain whether or not the beliefs I was raised with are actually justifiable - if there is any good reason to believe them.

Given that proper scholars with proper postgraduate degrees and proper academic posts in respected universities cannot agree on the authenticity of most of the gospel pericopae, then I find it hard, as an uneducated (in history or NT studies) guy to justify believing in (m)any of them.

"Carrier is an unemployed PhD graduate who has never held a professional position or academic post. He doesn't even understand the criteria he's criticizing."

Ah. 'ad hominem' criticism. As an employed PhD graduate (admittedly in engineering), who holds a professional position and academic post (at a respected university, by the way), I have seen the nonsense that some of my equivalently positioned colleagues occasionally come up with. An academic post does not guarantee quality. The opposite also holds. Someone who holds no teaching post can come up with a good case. You need to judge the argument on its own merits, not follow any genetic fallacy of assuming that because the originator doesn't have a job, that the argument must be flawed.

And besides, you are criticising him from behind a faceless pseudonym. Do you have tenure?

Fortigurn said...

"But if some or all of the only tradition we have for the person or event is found to be inauthentic,"

If all of the only tradition was found to be in authentic, we would legitimately question historicity. But in this case a significant amount of the tradition we have is considered authentic, and we have two independent historical witnesses to the historicity of Jesus; Josephus and Tacitus (I'm being generous by excluding Suetonius, though there's no reason to).

"As far as I can tell, the quest for the 'historical' Jesus presupposes that some of the pericopiae are authentic and that some are inauthentic - that is, that the stories do not go back to the historical Jesus, that is we have no way of knowing if he said or did some of the things attributed to him in the Bible stories."

It doesn't actually say we have no way of knowing if he said or did some of the things attributed to him in the Bible stories; on the contrary, the criteria of authenticity were established precisely to make such determinations.

"Even if the questors don't admit it, they are either seeking to validate everything in the Bible for apologetic ends, or they are seeking to redefine Jesus as something other than described in the Bible, usually for anti-apologetic ends."

I see no evidence that these are the only two motivations of those involved in the Jesus Quest.

"Given that proper scholars with proper postgraduate degrees and proper academic posts in respected universities cannot agree on the authenticity of most of the gospel pericopae, then I find it hard, as an uneducated (in history or NT studies) guy to justify believing in (m)any of them."

That is not a legitimate reason for dismissing them all. You have neglected to acknowledge the core body of pericopae on which scholarship has reached consensus.

"Ah. 'ad hominem' criticism."

No. Ad hominem is the illegitimate dismissal of an argument on the grounds of alleged character flaws of the proponent. I did not do this. You said you thought Carrier was a historian, and I corrected you, explaining his actual position; I stated verifiable facts concerning his employment record.

I did not say that Carrier's unemployed status and lack of academic position invalidates his argument concerning Bayes' Theorem (or any of his other arguments). I did say he does not understand the criteria he is criticizing, and I have already proved this. But I did not say this invalidates his argument concerning Bayes' Theorem (or any of his other arguments).

"An academic post does not guarantee quality. The opposite also holds."

That is not in dispute. But someone who criticizes the consensus of professional historiography, without actually engaging with the work of the professional historians responsible for the consensus, is clearly missing the mark. Disputing the criteria of authenticity does nothing to overturn the professional historiographical consensus on the historicity of Jesus.

"You need to judge the argument on its own merits, not follow any genetic fallacy of assuming that because the originator doesn't have a job, that the argument must be flawed."

I agree. That's why I didn't do any such thing.

"And besides, you are criticising him from behind a faceless pseudonym. Do you have tenure?"

I login with my Google account, which shows a personal photo and my real name. If that doesn't display for you on blogger.com, that's the fault of the Blogger software, not my fault.

I don't have tenure, and only my Bachelor degree is in a relevant field (double classics major); my Masters degree and my current PhD are not. But that's irrelevant, because I am not appealing to my own authority or qualifications; I have cited the relevant scholarly consensus, and I have made objectively verifiable statements about Carrier's employment record and the fact that he is wrongly referring to criteria of AUTHENTICITY as criteria of HISTORICITY.

Ricky Carvel said...

I think I'll draw this discussion to a close.

I'm sorry I ever (mis)used the word 'historicity' in my review, and I now understand why I was wrong to do so. I'm still not convinced it makes much difference, but as a pedant I like to use the right words, so I'll try and be correct in the future.

I note that Carrier does use the word 'historicity' in his book about twice as often as he uses the word 'authenticity'. But then again, the stated aim of his next book is to challenge the consensus on the historicity of Jesus, so we'll see how he gets on with that when the next book comes out.

As for Carrier's pedigree, I'd say that having a Bachelor's degree majoring in history and having a PhD in ancient history does make him a 'historian', and I think his publications and conference presentations show that he is "engaging with the work of the professional historians" even if he is doing so without the benefit of a proper teaching position.

Finally, when I click on the link of your pseudonym (maybe it is your name, I don't know), all I get is a generic 'about me' page with no photo, no name and no info. The only info is that you've been on blogger since 2011. Maybe you need to tweak your settings?

Fortigurn said...

1. I am not saying Carrier is not a historian, I am simply pointed out he is not a professional historian nor currently holding an academic teaching position. I made it clear this does not invalidate his work on the subject at hand.

2. If Carrier is engaging with the relevant professional historical commentary on Jesus, it will be cited and referred to in his work and his work will be published and peer reviewed in the relevant professional literature on historiography. Thus far I haven't seen evidence of this.

3. It seems the Blogger software is not linking you to the Google account with which I sign in. I do not have a Blogger account; the page you see simply records the first time I commented on Blogger.