13 October 2010

Doubting Thomas and a scientific approach to theology

It is my firm belief that that which is true cannot be proven to be false. That doesn't mean that a true thing cannot appear to be false, given an incorrect presentation of of facts are withheld.

But proof should not be mixed up with evidence, they are not the same thing. Proof is conclusive and final; evidence only points towards truth and must, as much as possible, be corroborated with other evidence pointing in the same direction.

For example, I could prove to you that there exists no rational number which, when squared, equals two. This is an exercise in mathematical logic. I could not, however, prove to you that the Riemann Hypothesis is true. [For those of you without a science background, the Riemann Hypothesis is related to the distribution of prime numbers and basically says that a function (called the Riemann zeta function) has non-trivial solutions only if those solutions take a certain form.]

The fact that every single solution to the problem conforms to the hypothesis is strong evidence for its truth but does not prove it irrevocably. That is why it remains an hypothesis and is not yet elevated to a status of a theorem.

Yet this has no bearing on its truth. Either the hypothesis is true or it is not. Evidence only informs our opinion of whether or not something is true.

Faith is taking all the evidence that is available to us and saying “I believe this is true.” Once you have reached a position whereby you can ascertain what you believe to be true, then the life of faith is living as though it is true.

Think of a Venn diagram. The largest set that we want to consider is the set of all things that are true. A subset of this, entirely contained within the set of truth is the set of all things for which there is evidence. This is where we make a break from the logical positivist school of thought.

This form of thinking is particularly prevalent amidst the more militant atheists who insist that without physical evidence of the existence of God, at the exclusion of all other possibilities, the non-existence of God should be the status quo of reasonable thought.

However, this is very simplistic thinking and demonstrates an extreme form of closed-mindedness. To presume that nothing can be considered true without evidence denies some very basic truths, and some fundamental theorems of mathematics which have been proven to be true. For example, the proof of the irrationality of the square root of two is reliant on a proof by contradiction. But this methodology has no meaning to a logical positivist, so is a tool they cannot use. And without it, you cannot prove that the square root of 2 is irrational, which we know it is. Therefore logical positivism acts as a set of blinkers that blinds you from seeing some truths. Additionally, the idea falls on its own sword when you apply the reasoning to the philosophy itself; it's rather like Medusa looking in a mirror.

Returning to the idea of proof and our Venn diagram, the set of things that can be proved is a small subset of the things for which there is evidence. This set is remarkably small given how stringent the criteria are for anything to be proved.

Usually, if I ever hear someone talking about proof, it is my cue to stop listening to them, since a failure to distinguish between evidence and proof is the hallmark of someone who doesn't understand what they're talking about. And if they ever use the phrase “enough proof” then my blood starts to boil and steam starts coming from my ears.

So for most practical purposes, proof is simply not obtainable. But this doesn't stop the world turning or prevent us from carrying on with our everyday lives. The point is that the unavailability of proof does not deny truth. Something can be perfectly true even if we can't prove it to be so. In the absence of proof, the next best thing would be an overwhelming body of evidence.

So then, let's have a little think about evidence. What constitutes evidence? You could ask a host of difference people and get a different answer each time. It will depend on their professional background, education and yes, religious inclination.

I won't advocate anyone else's point of view here, I'll just give you my opinion, which you are welcome to disagree with and debate. Evidence is a signpost to truth. It can come in many different forms. The nature of a signpost is that one by itself won't get you to your destination; you need multiple signposts to guide your way. Similarly, one piece of evidence is rarely enough to form a valid opinion on what is true. This is why the scientific method requires corroborative evidence. That is, you can find multiple pieces of evidence that all point in the same direction.

Now we can move on to discuss the quality of different forms of evidence. There is a very good treatment on this subject in Lee Strobel's book, The Case for Christ. I understand that he has written some follow-up books to this, but I cannot comment on them since I have not read them.

The essence of it is that different forms of evidence can be of vastly differing use. In a court of law, eyewitness testimony is extremely valued. But one eyewitness is rarely enough. Their testimony must be backed up by other eyewitnesses or by alternative forms of evidence. In science, eyewitness testimony holds no credence. This is nowhere better demonstrated than in furore over cold fusion. Two scientists claimed to have seen it, but they had no corroborative evidence to back them up and their methodology, when repeated by other scientists, did not produce the same results. Consequently, their work was discarded and their credibility irreparably damaged.

The point is, even though evidence points to truth, we are not always great at following the evidence. Given one clue, multiple hypotheses may be concocted that are in accordance with that clue. If we then find a second clue, then we can refine our search for truth. Given that any evidence is open to interpretation, it must therefore be open to an incorrect interpretation.

From here, we can move on to the concept of intellectual integrity. If we cannot establish the truth of an issue via proof then evidence is the best thing to look for. But in this instance (which actually accounts for the vast majority of our experiences) we have to allow for further evidence to become available later and which may change our perception of truth.

To do otherwise would be arrogant and closed-minded. While some truths change (e.g. I live in Sussex, but I won't always) and some don't(though I hesitate to give examples, just in case I’m wrong), our perception of these truths can constantly change. So when I often hear the accusation that theology cannot progress yet science can, I am quick to point out the absurdity of that comment. While, as a Christian, I don't believe God changes, my understanding of him does. Similarly, the laws of physics don't change but my understanding of them does. So theology can progress just as easily as science can, based on the evidence available to inform our opinions on them.

So far, we have only discussed the scientific method and some of the philosophy behind it. We don't seem to have touched on the title of piece. To get a little more personal, I have two main methods for studying the Bible. One is the systematic method, where I go through a book in detail and follow up on all cross-references to ensure that any of my interpretations of scripture are consistent and well-grounded. The other is to the thematic method, where I re-examine my beliefs. This involves thinking through a particular topic and then searching through the Bible to see if what I believe is Biblically based and changing or refining my view based on the outcome of that study. First, I seek backing for what I do believe and then carry on my search for other aspects that have, until now, eluded me.

If the point of this exercise is not yet clear to you, then please go back to the beginning and read from the start again.

The Bible is the best source of evidence the Christian has. Now at this point I can almost hear the howls of derision coming from the atheists. And in the other ear are the cries of the fundamentalists who will refer to various Bible verses as a back-up for this statement. Neither of these positions is sustainable, though.

The scoffers ignore the huge body of evidence that points to the authenticity and reliability of the Bible, through centuries of scholarship and textual criticism. Likewise, those that point to any Bible verses as back-up have been caught in a snare, as it is a circular argument. In order to rely on the Bible as a source of evidence, you have to seek corroborative third-party evidence.

Now I don't have the space here to go into all the details, and there is plenty of work done by scholars who are far better than I. If you are interested, and want to pursue this line further, then I would recommend you read Nothing But The Truth by Brian Edwards as a starting point. This line of study does come with a health warning. Many people have devoted their lives to this line of study and if you want to get on with your own Christian walk, then this is just a starting point, but it would not be productive to get bogged down by it.

So then, one of my recent studies was to challenge my opinion that a scientific approach to theology is the best approach. The reason for that is because I spend a reasonable amount of time defending the Christian faith against attacks from atheists. One of the most common attacks is the claim that faith is belief in the absence of evidence, and therefore no reasonable or rational person could hold a position of faith without compromising their intellectual credibility. Another attack on a similar line is that the Bible encourages faith over evidence and that believers would do best to believe without critical thinking.

Key to this view of Christianity is the story of Thomas after Jesus' resurrection. The story goes something like this: “After Jesus rose from the dead, there were a large number of witnesses that testified to having seen him alive. Word reaches the disciples who are delighted, except for Thomas, who refuses to believe it until he has seen Jesus for himself and examined the wounds in his wrists and side. Jesus allows Thomas to examine the wounds but Thomas is thereafter vilified as having no belief and that those who believe without evidence are the heroes of the piece.”

So let's have a look at the evidence for this. First up, the book of Matthew. The amount of narrative regarding the resurrection is minimal and there is no mention of the Thomas incident at all. Our next candidate is the book of Mark. The resurrection account here is a little longer that Matthew's, depending on your opinion regarding where the book ends. This is quite an interesting story in itself, but I'll let you look into that yourself.

Thomas is not named in the longer ending, but reference is made in verses 12-14: “After this, [Jesus] appeared in another form to two of [the disciples], as they were walking into the country. And they went back and told the rest, but they did not believe them. Later he appeared to the eleven themselves as they were sitting at the table, and he upbraided them for their lack of faith and stubbornness, because they had not believed those who saw him after he had risen.”

As much as I love the term 'upbraiding' for its imagery of lifting someone by their long hair, it isn't one that I would use in everyday language. So let's look a couple of alternative translations to try and get a more well-rounded version. The NIV uses the term 'rebuked' and the Amplified goes for 'reproved and reproached.'

So this would appear to give credence to the notion of praising belief without evidence. We'll come back to this later. In the mean time, let's continue our whistle-stop tour of the gospels with a look at Luke. This has got a lot more detail in it, though yet again there is no explicit mention of Thomas. What we do have is the reason for Jesus' rebuke. In verses 25-27 Jesus explains why his resurrection should not come as a surprise. Later on, in verse 39, we find Jesus actively encouraging the disciples to examine his wounds to determine that it is really him.

So if we compare this to Mark, it would appear that the reason for Jesus' rebuke for a lack of belief is that his resurrection should have been expected, based on the evidence that the disciples had been witness to during Jesus' ministry.

This is an example of what I was talking about earlier about evidence acting as a signpost. Given the Mark passage, there are a number of possibilities of how to interpret it, some of which are more obvious than others. When we then gathered further evidence in Luke, this helped to clarify the Mark passage and helped to direct us in a more specific direction that was not the obvious route we may have thought at first.

Finally, we need to come to the gospel of John. Like Luke, this book contains quite a lot of detail of the post-resurrection period. But at last, we do find mention of Thomas, so all those rumours about him may not be unfounded at all! Rather than copy it all out here, I would encourage you to read John 20:24-29, though for context it would be good to read the whole chapter.

What we find is Thomas saying, “Unless I see the mark of the nails in his hands, and put my finger in the mark of the nail and my hand in his side, I will not believe.” It was a whole week after saying this that Thomas gets the chance to do this. I can only speculate as t the kind of conversations he and the rest of the disciples had during that time, but I imagine they might have been a bit frosty.

Interestingly, when Jesus and Thomas are finally reunited, the first recorded words are not spoken by Thomas, but rather they were an invitation from Jesus to Thomas, asking him to examine him. At this point, Thomas acknowledges Jesus as Lord and God.

Yet the narrative in John does not record any remark of rebuke, but instead includes a line not included elsewhere in the gospels, which has an important bearing on our discussion. “Have you believed because you have seen me? Blessed are those who have not seen and yet have come to believe.”

There are some who take this as an endorsement from Jesus in belief without evidence. After all, wasn't it quite reasonable for Thomas to doubt the testimony of the other disciples and to seek corroborative evidence? The above would seem to imply that the answer is no. But let us hold judgement on that before we've looked for some other corroborative evidence, outside of the gospels.

One verse that I have had quoted back at me a few times is this from 2 Corinthians 5:7 “for we walk by faith, not by sight.” True as that may be, it immediately strikes me as a soundbite, taken out of context. So what is the context in which it rightly belongs?

The surrounding passage talks about our bodies as being temporary, likening them to tents that contain our inner nature. Yet it is this inner nature that remains unseen. As much as our romantic sense would like to differ, you cannot look directly into a person's soul. Going back to verse 16 of the previous chapter, our inner nature is being renewed constantly (c.f. Romans 12:2). So to say that we do not walk by sight is not an endorsement of rejecting evidence; rather it is an encouragement to focus on more spiritual matters.

The New Testament has a lot to say regarding warnings against false teachers. Staying in 2 Corinthians for a bit, the first half of chapter 11 is devoted to them. Or take Matthew 7:15-23. It says “by their fruit you will recognise them.” So there is evidence that will allow you to discern between good teachers and false teachers. Similar analyses can be found in 1 John 4:1-3 and Revelation 2:2. These relate to putting them to the test.

So why is this important? Why is so much attention paid to weeding out the false teachers? Well, the answer is quite simple, they're a huge risk. There wouldn't be a warning against something that didn't exist, so they were evidently a problem in the 1st century A.D. They are are no less a problem in the 21st century. The rise of the internet has allowed the messages of the poorly informed minority to gain a wider audience. If we do not show discernment by comparing what we are taught against scripture, then people will get the wrong ideas and these will spread. It doesn't take long to find some very dodgy stuff on the web. Yet it's not particularly hard to spot the false teachers; so it is something of a wonder that so many people are taken in by them. And of course, please test what I have to say as well and correct me if I am wrong on any points.

Some of the key indicators are the call to abandon discernment. Lines like “don't think, just believe” will get me running for doors, as will anything with the stench of the so-called “prosperity gospel.”

OK, so that was a bit of a sidetrack. To recap the key points: test, evidence, discernment. These are the things that are valued. So the case for blind belief is looking a bit shaky in the face of the evidence-based approach.

But there are a few passages left that could inform us further. Take a read of James 2:14-26. The key verse here is verse 20. “You foolish man, do you want evidence that faith without deeds in useless?” So what is this saying? That to demand evidence is wrong? Some might take it that way, but perhaps a less dogmatic approach would be to consider what this sort of wording means today. If I were to say to you “You silly person, do you want evidence that I went to university?” then I am not refusing to give evidence or denying that it exists. Rather, I am expressing exasperation at the failure of someone to see a point that they should already be aware of. The verses that follow the passage above are indeed James giving the evidence.

There are plenty of other passages that one could look at. For starters you could count the number of times discernment is mentioned in the book of Proverbs.

So what is our conclusion. My understanding of scripture is that blind belief is not a virtue. We have to examine and test what we are presented with and form our opinions and values based on those. Faith is not a cop-out, it is the bridge that takes us from evidence to truth. I will leave you with this from 1 Thessalonians 5:21

Test everything; hold fast to what is good.


  1. I came to your website via a link you posted on the Guardian website I believe. You have written a very interesting article/blog/post(delete as appropriate).
    I must admit I have on half mulled over these thoughts that I will proceed to share with you and so if they are not quite as well written as they might I do apologise.

    This is becoming a more frequently occurring situation that one finds himself to be facing, that is a person of religious beliefs who conjectures the said beliefs to be A rational and B eloquently sets out an argument that includes scientific knowledge. Although perhaps the Riemann hypothesis is more mathematics.
    One of the criticism I have is that although you mention one cannot rely on verses in the bible to provide evidence that the bible is true, you chose not to mention the sources that back the bible up a historically accurate. Which would have been even more interesting that the subject about which you have written.

    However the main issue circulating about my brain is the theme you hang your argument upon that (christian) religious faith that involves testing and holding onto that which is true, is a superior stand point to the "militant" atheist perspective that in the absence of evidence for a deity, a null hypothesis is appropriate.

    I would differ in opinion, I believe this centers entirely around whether you interpret the bible as reliable or hogwash used as a means of mass social control.

    Now I'll be the first to admit that absence of evidence is not evidence of absence however, if you believe that the current evidence available (in the case the bible and the sources supporting it you mention) to be unreliable or dubious then adopting the "militant" atheist position is not unreasonable. One may conjecture why not agnostic? But if you have examined several religious explanations of god's existence and the "proofs" of them lacking then ones skepticism may deepen (very reasonably) and lead one to believe that a god does not exist. Now I would suggest that this is not close-minded, and proffer that combined with atheistic arguments to the vast improbability of a deity is entirely reasonable.

    Coming back to an earlier point about themes, testing and holding fast to what is good, a simplistic thought entered my mind when I was very young and has never been satisfactorily answered and was not answered by your interpretation of Thomas here either. Is that if god does indeed want us to test everything and hold fast to what we find to be true, then why do we find all sorts of contradictory observations, to say for example genesis. If evolution is not true and we were made as we are only a short amount of time ago then why do our reliable tests and observations find that it is not good? (but perhaps I assume too much and perhaps you are neither a creationist nor a "intelligent design" advocate). After all we would only have to find precambrian rabbits to disprove Darwin, surely it wouldn't be too hard for a deity to place one next to a christian archeologist?

    Neither from my view point does the testing and keeping hold up the moral standpoints that are often held up by Christians eg. that murder or killing can never be justified. Yet in the old testament the Deity him/her/itself is capable of genocide and nearly xenocide and yet he is perfect. The being apparently possesses knowledge of such matters that might make our heads hurt.

    I bid you farewell in case I forget to check for any response, and as always turn away with the sad thought that I only believe you to be incorrect where as in all likelihood I am believed to be destined for eternal damnation shortly after my cells cease to function.

    Presumably my crime being testing everything, finding all is not well and holding fast to the principle of testing everything, which actually the deity may seem to advocate. Ironic.

  2. Dear Lewis

    Thank you for your well-considered and thoughtful comment. I think it deserves a fuller response than this short comment. I have little time to write this week, as most of my blog posts are written over a weekend and then posted later in the week. So if you see any other posts going up, please do not think I have ignored you; I simply wrote them before I saw your comment. I hope to find time this week to put together some thoughts. So please do check back.