Quick note - review was done in a couple of stages, the first 6 chapters first, then the rest a week or so later
To start with, I know no Greek, so have to defer to the translation given, and in cases where two people disagree, can only weigh their arguments against each other. Similarly, I am not a historian, so have to take much of what is written on faith. I have read other mythicism books, and a few ostensibly secular ones on the evidence for the historical Jesus, though have found them to typically be circular, with many of the arguments relying on a presumption of historicity, or in some cases, little better than Christian apologetics.
While reading, I frequently found statements I was unconvinced by, but pretty much every time, Carrier acknowledged the problems and either justified them, or gave them low weight in his calculations. There are times when he can be a little repetitive (he has two fairly long sections on Romulus, saying more or less the same thing in different chapters), and to my mind, often labours a point much more than is necessary, but perhaps with a controversial idea such as this, you really do need to give people as little chance of a get out as possible.
I come into the book largely on the side of mythicism, having being convinced that there is a good case, and that the case for Historocity is weak starting from Earl Doherty's book about 10 years ago up to Bart Ehrman's book a couple of years ago. To borrow the kind of language Carrier uses, if historicity were true, it is unlikely that a respected scholar could manage no better than that.
Going in, I had several starting premises
1) The Jesus of the bible did not exist – this is totally uncontroversial except with fundamentalists
2) The gospels are mostly fiction, based on retelling of Old Testament stories and other myth of the time – Again, this is a mainstream view. The main issues to be addressed is if there is any history left in, if such can be identified and if the gospel authors made up the stories themselves, or used pre-existing works or circulating oral traditions. I hadn't seen particularly good arguments on either side for this one
3) There is no useful evidence outside of the bible – it is all too late, or unreliable. This is a little more controversial, but is largely accepted by many people who believe in the historicity of Jesus
4) Paul describes mostly mythical Christ. There are a handful of instances where he talks in what seems like historical terms (though never giving actual historical details), that mythicism needs to explain, but there are also numerous instances where he either fails to mention Jesus or talks in purely mythical terms, which historicism must explain. The most common explanations for his silence, that everyone already knew the stories, so there was either no point in mentioning them, or it would be insulting, or alternatively, that his competition were the disciples, so talking about what Jesus said or did would draw attention to their better claim are totally unconvincing and not only completely unrealistic based on how actual people behave, but totally inconsistent with what we see from him in his writings.
By its very nature, this will be a controversial book, that is likely to receive many negative review. The vast majority of such 1 or 2 star reviews will be from people who have nor read the book, didn't understand it, or didn't pay attention, which will be clear if they argue
1) Mythicism has already been shown to be wrong.
2) Mythicism is a fringe position and all actual scholars consider Jesus historical.
3) We know Jesus was real because (insert favourite argument)
There is little to be said about the first two, but the third is one of the reasons this book, and the previous volume, "Proving History" are important. It is not enough to pick one or two verses, say "these seem to fit a historical Christ much better than a mythical Christ, case closed", you need to actually consider how likely such a passage would be with a historical figure or a mythical figure and then include this with all the evidence. That is what this book does.
There may also be objections based on
4) Carrier's Greek/history is poor and he mistranslates/misrepresents/misundertands something (in such cases, it is unlikely we would see evidence why the preferred version is better, but at least this has the potential to be a valid argument. It is not really one that is easy to assess for a non expert, especially if it is just presented as an assertion
The first chapter introduces the problem and gives an extremely brief summary of the history and current state of the subject and the aims of the book.
The second chapter discusses what the minimal theory of historicity should be, concluding it should be the fairly obvious idea that a man known as Jesus acquired followers, some of whom claimed he was executed and soon after he began to be worshipped as a god.
The third chapter does the same for mythicism, but finds, without really going into any details that many mythicist ideas too outlandish to consider, so is much more specific, that Jesus was a celestial deity who communicated through divine inspiration, was incarnated, died and resurrected in a supernatural realm and that allegorical stories were told of this that later came to be viewed as history. Carrier does a good job showing this kind of thing was not unheard of, while acknowledging the specifics are unique for each and does not consider the cultural variations to be a problem. Some would probably disagree here, but this is special pleading and they would not make the same objection to his other examples.
Taken together, the first three chapters establish the plausibility of mythicism and the inconsistencies and weakness of historicism. This is probably evidence of Carrier's bias here, and the treatment is a little uneven, but with the Bayesian analysis employed, the tone of this section is essentially irrelevant.
Chapter 4 gives background on Christianity, with particular emphasis on mythical elements and similarities to other cults. Hardcore historocitists are likely to find fault here, though in truth, there is little controversial, except perhaps the idea that the early Christians believed their knowledge of Jesus came from scripture, but this is adequately supported., at least for those Christians we have evidence of.
Chapter 5 is a continuation of 4, but focusing on other pagan beliefs and religions at the time and their similarity to Christianity. Of particular significance is that he clearly establishes that dying and rising saviour gods were well known before Jesus. This again is likely to meet criticism from scholars who will claim that because they are not identical to the form Christianity took, they can be dismissed.
Some of this, such as Christianity being a mystery cult with secret teachings seems a stretch, and it may be that Carrier is cherrypicking here the one or two quotations that support this point, and I lack the background knowledge to assess it, but even if so, I don't think this has much influence on the final outcome.
There is much in these chapters that is presented from a mythicist point of view and any serious attempt to defend the conventional view of Christianity's origins will need to counter this, or at least show it to be relatively minor compared to the overwhelming evidence in favor. I also suspect there will be complaints about his use of the apocrypha here, thus showing they failed to understand the argument, as he does address this.
For chapter 6, Carrier works out the prior probability, which is basically the starting value he will put into the equation. He uses Jesus excellent fir as a Rank-Raglan class hero, which he demonstrated in chapter 5, and for which members are typically mythical. This may be another weakness, as there could be other classes used to establish the prior, which would give a higher value for historicity (for example, if we date the first gospel to 80AD, then "all people who had biographies written less than 50 years after the events in them were set" could be one). This would likely make little if any difference, as the Rank Raglan data would then come into play later on, and might even decrease the odds of a historical Jesus, as Carrier fudges the data here to make the prior higher than the actual results would warrant (he is quite open about this). A second possible issue here is that he picks "people who score more than half" a his basis, but doesn't seem to justify this. Again, if he had picked a higher number, it would have altered the actual prior, though not the one he uses, but I don't know what if he had chosen a lower value. How low would he need to go before actual historical figures would be included, and would they be outweighed by the addition of more mythical ones? It may be that this is addressed, and I missed it, but either way, I don't think it effects the final result, it is just something I would like to have seen. Carrier has argued outside of the book that other values would either give too much or too little data, and that there are no other suitable reference classes, but I haven't found this convincing and it should be demonstrated, rather than asserted, though this can be the job of anyone who decides to honestly address the issues.
Chapter 7 is an introduction to the evidence that will be used - extrabiblical (both religious and secular) and biblical (gospels, epistles and Acts) with an explanation of how we will assess them and what criteria he will use to accept or dismiss. Right from the start, he states that late documents, unless there is very good reason to believe they show an independent tradition, are to be excluded, which rules out anything after 120AD. Again, Christian apologetics may include such things, such as Lucien and Mara Bar Separion, but the use of these reeks of desperation anyway.
Acts, Carrier concludes is fiction, which to my knowledge is again not particularly controvertial. It is certainly full of fictional and mythic elements, with characters who fail to behave like real human beings. He argues that the content is evidence against minimal historicity and this was not something I found convincing – one of his prime examples was the way Jesus' family (and other characters, but mainly them) just disappear. This seemed to be arguing against a specific theory, not the minimalist one he had earlier set up. Most of the evidence in this chapter doesn't upport either theory, though I agree that the example of Paul's Trial, when nothing is said of any historical Jesus does slightly argue for the mythicist view
Next, he comes to the gospels. These have already been shown to be mostly fiction, with Mark as the first gospel, based on retelling of Old Testament stories and then Mathew and Luke expanding and redacting it, finally John being largely independent, though probably influenced by Luke, based on several similarities in stories and elements that are clearly mythical. Carrier accepts the traditional dates for this, and although he allows for a fairly wide range, the dating seems to be irrelevant to hi thesis as it is not given any particular consideration. He demonstrates that the consensus of fiction is correct and that Mark came first, retelling the Old Testament passages with a Homeric theme, and that much of the content, that is confusing otherwise, makes sense in this context. He argues that if there was a historical Jesus, nothing of his life made it into the gospels, and in the unlikely event it did, it is impossible to identify. He thinks this in itself is evidence against a historical Jesus, as it is unlikely that the writers would have no interest in anything their founder actually says or does but does not use this in his calculations as he has used the overall arc of the story to set up his prior probability. I think there is enough here that he didn't use that this could have been included to further strengthen the mythicist case, though it wouldn't do so by much.
He also argues against the commonly held Q hypothesis, which is that Mark came first and that most of the extra material in Luke and Mathew came from a sayings gospel "Q" He doesn't really give the Q side, so it is hard to be sure, but it seems like the people who support Q are assuming historicity and that the authors couldn't have just made it up. On the basis that the gospels are fiction, the Mark – Mathew – Luke hypothesis seems plausible.
Finally, he looks at the epistles and this takes two main forms. Firstly, he considers the argument from silence, showing (and again being extremely generous to the historical Jesus theory), just how ridiculously unlikely it would be that Paul had no cause to say anything about Historical Jesus, either to bolster his own arguments or to refute those of his opponent, and demonstrates how staggeringly inane the historicists excuses for this gaping hole are. Secondly, he looks at the passages claimed to represent Paul talking about a historical Jesus. Much of this is highly technical, which makes it hard for the non expert to judge, but it seems plausible, and he at least shows that the historicist tactic of pointing to these verses, saying they are about a historical Jesus and not looking at the context or implications is woefully lacking in any sort of critical analysis. There are a couple of weaknesses in this section, one time, he talks of how Paul is writing of people preaching another Jesus, which he assert must be a mythical one as Paul could say this if his Jesus was celestial, but not if he was historical. He doesn't back up this claim at all. Another time is talking of the "Brother of the Lord" phrase, where he talks of the theoretical need for "policing of terminology" which seems a straw man.
He also considers the argument that Pail specifically talks of Jesus in mythical terms, though this is mostly spread throughout the chapter, making it difficult to see it as a whole. They exceptionto this is Hebrews, which he analyses in details. It is worth noting that Carrier finds this to be one of the most obviously mythical books in the entire New Testament, which seems very much against consensus, the NIB New Testament survey for example claiming "No New Testament writer presents a more human Jesus than does the author of Hebrews" Having read both chapters, it seems that the author of the New Testament survey chapter was simply reading on the assumption of historocity and thus interpreting in that manner, even when it required a strained reading, though to be sure, I would want Hebrews in front of me as well, to compare it to both set of claims.
Overall, the conclusion is sound, thought is argued from a mythicist point of view. I can't think of anything relevant that a Historicist would include that would shift the probabilities much, and I don't think anyone who is being intellectually honest would use values much different for the historicist position to the ones Carrier uses, especially as for his "most likely" scenario he is excessive generous to the historical position and some of the numbers he use are untenable
There are occasions where they mythicist theory explains too much – he frequently says that something is consistent with Jesus being a myth, so is 100% likely, but even if it is consistent with a historical Jesus, it is not considered 100% likely, which is to say that the "possible v probable" judgement is used a little more strictly on the historicist view that mythicist one.