Why aren't the gospels reliable?

Are the gospels evidence for a divine being? And further, evidence that Jesus was the son of that being? It should come as no great surprise that I'm not the first to ask those questions, and I shan't be the last. The historicity of Jesus is probably a topic which historians have given more undue attention to than any other. Please note, I am not a historian, not even particularly knowledgeable about historical events or even methods of historical analysis. So when coming out as an atheist to Christian friends, it was a question I wasn't really expecting. I had put more of my efforts into more "a priori" arguments about deities, and not thought about historical evidence. Ideally, properly appraising the evidence would mean hours of research and proper tuition. But I can afford neither the time nor the money of a tutor, and even then I wouldn't be able to hold a candle to the sheer volume or quality of historians before me. I can however try to produce reasons as to why I may dispute the evidence. Here I hope to formalise my argument a little more, and cache it for future use.

Context and implications

Existence of divinity is an extremely important claim, it requires a huge amount of evidence. I can accept that Julius Caesar did this and said that with fairly large margins of error. The reason I can is that it really doesn't matter to me. Historical evidence of a deity and especially the link of one person to said deity is a really important question. If such a deity is real, I need to profoundly change my behaviour; it's not something I am going to accept without very certain evidence. In other words, I am sticking to my null hypothesis because of the huge implications of the tested hypothesis. At this point, you may feel an urge to tell me that this makes me evil, as if I am somehow avoiding God. I can demonstrate the circular nature of this with two arguments. Firstly, imagine you tell me that by jumping off a cliff I will achieve eternal happiness and life. In this case, the consequences under my current theory (no belief in any such supernatural mechanisms) are dire. I would need stupendous amounts of evidence to convince myself to do it. It is the same for religion, it will literally change the way I live, that's a big deal. Secondly, you would exercise the same caution when evaluating other religions and their books, and you would implore me to do the same if I was to look at the historicity of Muhammed. If you are compelled to reply to that with, "I have looked at Islam, and it really was silly and unbelievable", just seriously consider whether perhaps your cultural or confirmation biases would have affected your judgement at all. For more about my choice of the null hypothesis, read this post.

Bayes' Theorem

One qualitative assessment of Bayes' theorem is the need to consider prior evidence. If you'd rolled a dice 1000 times and every time it came up a one, and a friend told you that your next roll would be a six, you should be a little skeptical. You would also be skeptical of a historical document which talked about unicorns and dragons, because you have never observed any yourself. This is not unreasonable, the claim is extraordinary, and to quote Sagan: "extraordinary claims require extraordinary evidence". If a historical document said that people generally went about doing normal peoplely things in the past, we'd be much less critical of it. It is not wrong to "view" the bible in such terms, it is indeed correct to require extraordinary evidence for the claims of miracles and of deity.

To use a further example: if you found a video of me shooting a laser out of my mouth, would you believe I possessed a power like some kind of gastronomical Cyclops? No, you would view the evidence in light of what you know about me, and about the source. You've never seen anyone shoot lasers out of their mouths, and you'd probably be right to say it's impossible within our current understanding of physics. Furthermore, you know that videos are easily and convincingly faked. It would be ridiculous and naive to believe I could. Of course, with the bible it is not so obvious, but think about the concepts which would lead you to reject or accept such claims.

Were they lying?

I was asked several times whether or not I thought the gospels were faked. I see this as a false dichotomy, on one end the early church conspired to mislead us and on the other, the whole bible is literally (like literally literally) true. In reality, humans are capable of everything from outright lies to honesty, but there's a lot in between where intentions are good but the outcomes are false. Biblical experts widely agree that none of the gospels were written by eye witnesses. It is perfectly plausible that the facts about Jesus were escalated, getting more and more fanciful as traditions began to form and people began to get caught up in this new messiah. Like a game of Chinese whispers, an increasingly fascinating story on top of someone who was probably a great teacher. Naturally, the accounts may all be true, but it is most certainly a large leap to suggest that it amounts to evidence. It is circular at best: there is a plausible pathway to the gospels being formed and not being literally true.

But how did a lie convince so many people? They plead. As people we are bombarded with huge amount of information from birth. Much of what we learn is simply copied and pasted from our culture and parents. Once a religion takes hold, it stays, and as I have mentioned before, strong religions remain. By definition. The weak religions die much more easily so the only ones that are left are the convincing ones. Obviously this is a theory, but it shows that there is a possible mechanism for convincing religions to form without any real truth behind them. Also, this argument falls apart when we consider other religions. How about Islam vs Christianity, both religions deny the authenticity of the other. Clearly convincing incorrect religions can form, convincing in fact to 2.2billion and 3.3billion respectively. People don't tend to lie, they bend facts with a whole slew of biases. Humans are really terrible sources for many reasons, especially in a religiously and emotionally charged environment.

Conclusion

The problem with looking back and making theories around the evidence is that there are an infinite number of possibilities that fit with any given set of evidence. It is no surprise that both theories fit. This is invariably what happens with all kinds of historical theories, I'm not saying history is wholesale tosh, far from it. Historians know how difficult it is to make concrete statements about past events. Obviously, this applies to all historical theories, even the one that Jesus was not divine. With the bar for proving the existence of a deity is so very high and the theoretical quality of the source is so low, it is inadequate to make even a weak claim.

Critical Thinking: Fallacies and Bias

Introduction

You are a good person and correct about pretty much everything. Or so we like to tell ourselves on a daily basis. I'm not being facetious, we literally do. Our inability to correctly critically assess our own views leads to regular and serious social problems, examples include racism, rejection of good scientific theories and debilitation of our political system. Key to become more correct is understanding your own limitations, this is not a discussion of how to persuade people with fancy words or emotive devices, but how to strive to be less flawed. (Note to reader, this is as much an exercise to help me as you).

A fallacy is simply an incorrect argument, and they can come in any shape or size. Often what is meant by "fallacy x" and perhaps a more helpful definition is: an incorrect logical construction or argument which humans often fall into. Bias can mean almost the same in this context, a tendency for humans to think in a certain way which can often lead to incorrect conclusions. Some of these biases may even be obvious, you may palm off the severity of them, saying: "I notice myself doing these all the time and stop myself." Maybe you are a cognitive superman and stop yourself all the time, but I doubt it because you are most probably human. Even if you are exceptional, these biases take a lot of work to find and minimise. You will never be done either, it is a process of continuous improvement, it is both unhelpful and inaccurate to think you will ever finish. Enjoy instead every time you eliminate some bias, becoming a little less wrong.

Fallacies and Bias

In general (there may be exceptions), fallacies and biases stem from a few human traits. Firstly, we view ourselves in an overly positive light and others in a negative light. We dismiss our own flaws, and assume we are correct more than we are. Second, we are overly prone to type 1 errors (false positives). After all, it is better to over-sensitive and avoid a harmless thing than be under-sensitive and ignore a dangerous one. This, apart from making us survive better, means we tend to see patterns in events that aren't there. Another major issue with human reasoning is our tendency to see a discussion as war. We are built to form groups, tight knit groups who believe broadly similar things. This is obvious in politics, where battles which should be about ideas and data become battles about groups and parties (Check out Politics is the Mind-Killer on Less Wrong for more).

Lastly, and a more general point which encapsulates the others: we aren't designed for this. Long, certain logical processes may be accurate but they are slow. It's not all bad, as I said with type one errors, with our limited processing power evolution has provided us with decent heuristics to survive. Heuristics are essentially cutting corners when it comes to finding solutions. They are far more efficient than proper logic, even if not perfect, complete or always correct solutions. In days gone by, when our minds were preoccupied by more basic needs, this was great. In fact it is tautological to say, those who survived to reproduce were better at surviving in that primitive environment. That's great, everyone loves survival. The problem arises when we focus our mind on one problem, our heuristics cloud our vision; offering their needlessly quick and half-arsed ideas, when we have all the time in the world. Evolution is an imperfect process, and contrary to popular belief (due to our knack for type 1 errors) it did not and does not "aim" for a perfect being. In this case, it has produced a being which is not very good at logical deduction, instead one which is good at surviving and reproducing.

Confirmation Bias

Confirmation bias is a tendency for people to find evidence that agrees with their hypotheses. We don't like the feeling of being wrong or the effort of having to think to change our opinion (I'm speaking from experience). So as a coping device, we either avoid, suppress or deride such evidence. This can express itself in all kinds of ways. One example is when we seek out friends who agree with us, I'm not judging this practice as wrong, we all need down time (check out is-ought fallacy). Nevertheless, we should be aware of it, because sometimes it can lead us to another fallacy: the false-consensus effect (there are many other ways this can arise). We can also avoid conflicting evidence by only reading news-sources that agree with us. In the same regard we can be over-critical of people who disagree with us, (a little more of this later) or automatically put up barriers if we think they might. You may feel yourself do this, try reading two conflicting newspapers and feel yourself glide over one opinion but ridicule another. Of course, it is time consuming to do this, to question evidence you agree with and entertain evidence you don't (maybe you can see why we evolved this bias). I am by no means saying all evidence is equal, one important conclusion of Bayes theorem is that we take into account prior observations, but naturally we aren't sensitive enough (hence the bias). Don't waste your time seriously appraising evidence of the boogie-man, but do occasionally ask yourself, "is it my level of trust for this evidence reasonable or am I unfairly ignoring it/giving it undue credit?" And be willing to change your hypothesis in the light of sufficient evidence.

Attribution bias

Wikipedia sums this bias up very well with a story:

"For example, when a driver cuts us off, we are more likely to attribute blame to the reckless driver (e.g., “What a jerk!”), rather than situational circumstances (e.g., “Maybe they were in a rush and didn’t notice me")."

The situation acts in reverse when it is us cutting up the other driver, and although the bias is a little broader than this (and is very much worthy of a further read) it stems from a simple idea: we want to portray ourselves as positively as possible. To counteract this bias, remember that everyone else is like you.

Cultural bias

We see evidence through the lens of our current theories, we saw that in the confirmation bias. However, many of there theories are first formed and learnt from our culture. By culture I mean in the broadest possible definition, including the culture of your friend groups, the culture of humanity, the culture of your educational establishment etc. Perhaps it would be better to refer to it as environmental bias, what are the people around you saying? Again, this is a bias of magnitude not type, don't throw out everything your culture tells you; our ability to absorb and pass on huge amounts of culture is one of the few things which separates us from other primates. Remember that nothing is sacred, no idea above reproach. The fact that religion practically runs in families should serve as a stark reminder to question received knowledge. Cultural bias can be much more subtle, one interesting example is the obsession of western nations to enforce democracy on countries with authoritarian rule. However, we are surprised when the country votes for a despotic leader again, "they are silly", we exclaim, "why would you not want a secular and liberal democracy?!" Culture is powerful and paints everything you think: question the accepted norm.

Ingroup-outgroup formation and bias

This is a particularly toxic bias: we love to make sides, seek to widen gaps and reduce proper argumentation to throwing shit around. What do I mean?

We need no encouragement to produce sides, as the robbers cave experiment suggests. I would highly recommend reading it, but to quickly sum it up: two isolated groups were formed, and upon discovering each other, started a constantly escalating war which also standardised behaviour within the groups. See also, the two sided debating chambers of the House of Commons and the Cambridge union. But what is wrong with a bit of back and forth in a debate as long as we don't fight?

Firstly, issues are rarely two sided or even three sided, the best solution (and remember that is our goal) is somewhere on a many dimensional map of the solutions (x amount of this and y amount of this... etc). Reality and people are complicated, and so are the solutions to our problems, I don't want a choice between only two. Furthermore, I and you need no encouragement to conform to a binary choice. That isn't all of it though, our tendency to take sides often leads to poor argumentation. We provide our own side concessions and don't question, all the while demonising and criticising the enemy. We see the discussion as a war, where our side needs to win. To question your side is betrayal and making concessions is losing vital ground. This serves only to widen the gaps as insults become personal, make our own views more ardent and produce a more stark binary. Choices are rarely binary so don't take sides, you are trying to find the truth not win a war.

In politics these effects are blown up and their effects are too terrible to fathom, I would recommend reading politics is the mind-killer.

Ad Hominem

A famous politician once concluded "Rarely is the question asked: Is our children learning?". He was stupid => his policies were stupid => we should do the opposite.

Ad Hominem is a decent heuristic, stupid person says stupid things, a bad tree bears bad fruit. But it isn't a valid method of refuting a specific argument. The truth of statement is entirely separated from the person saying it. If you have enough time, there is no need even to consider who is saying it. Simple statements about whether one thing implies another require no context. With all the time and resources in the world, more complex claims could be tested with your own evidence and all logical steps could be checked. Realistically though, it is useful to have context and possible motivations if it is a particularly complex argument. It is useful to know where someone is coming from to watch out for specific flaws, but remember when you do it. In your mind, you must separate the person and the idea. (To link it to the previous bias, bear in mind a discussion is not a battle between two people or even ideologies or cultures, the truth is unconcerned with the frame and participants of the debate.)

I feel I must defend poor George Bush, in my example I remarked at his grammatical slip. On this basis and on his mannerisms, you may conclude that George Bush was stupid, maybe he was. I don't care to be honest, good grammar and spelling are probably only weakly correlated with intelligence, or at least weaker than you think. Even if it was, it wouldn't be the point, the truth could appear badly spelt on the side of a railway track or uttered by a pompous fool and it would still be true.

An extension of this fallacy is the tendency to reject wholesale the views of the stupid or the evil. I don't think I can explain this any better than Eliezer Yudkowsky, see Reversed stupidity is not Intelligence.
The stupid and evil occasionally get it right.

Is-ought fallacy

The is-ought fallacy is the movement between statements of reality and statements of ethics without suitable justification. How things are (is) and how things ought to be are separate questions. We see a specific type a lot, when people appeal to nature; flogging food with all "natural flavours" and accusing homosexuality of being unnatural and therefore wrong. It's not that either statement must therefore be wrong, it just requires justification (you'll probably struggle more with the latter statement, I hope).

The connection between reality and morality should be reasoned and not simply implied.

Conclusion

These are literally a tiny sample, check out List of cognitive biases on wikipedia (less wrong also has some very good articles on such things). I have attempted to pick particularly common ones, but this is of course shaped by my experience and personal biases. Perhaps you would have picked different ones, but that's not the point, I just wanted to point out to you (and me) how often and how badly wrong we are. The answer to "why?" might be from our culture and genes, but don't blame your ancestors too much, wondering whether we are in the matrix isn't very helpful when a tiger is bearing down at you. If your ancestor had been having an existential crisis at that point, you may not be here to read this (maybe you wish s/he had). Corner cutting heuristics are much quicker, but take your time and don't skip the logical steps, there's often no need. If a decision is important enough to take your time about it, keep the logical steps short to avoid falling in such holes.