Judging by twitter Prof Richard Dawkins was his usual emollient and self-deprecating self on Radio 4 this morning promoting the results of a new Ipsos-MORI poll commissioned by his Foundation for Research and Science. I didn’t hear it myself so I won’t comment, but what of the poll itself?

The poll was conducted straight after the census last year (why they’ve held it back till now I do not know), and sought to identify people who described themselves as Christian in the census and measure in more detail what their actual religious beliefs were. Unsurprisingly it found they were not universally very religious. In many ways, this is an obvious finding. In the 2001 census 72% of so of people said they were Christian, but we know from survey data and church census data that most of these people don’t go to church, and from many other surveys that at least some of them don’t believe in a god. I wrote about it in more detail back in 2007 here.

Turning to the new survey, first off it projected that 54% of people had described themselves as Christian on the 2011 census. This would be a very significant fall on 2001 if it was the case, but it’s probably worth waiting to see what the actual census figures are before getting all excited about it. People answer censuses very differently to polls and the survey’s projection may end up being wrong.

Moving on the survey contains all sorts of stuff about whether people who put Christian on the census believe in ghosts and astrology, or whether they know which books of the Bible come first and similar stuff which the press release from the RDFRS gets excited about, but basically it boils down to what we already know – some of the people who put Christian on census forms would not be Christian by some other definitions.

Cutting through the chaff on this the best questions to actually illustrate this are these:

– Q16 on whether people believe in God. Of those who put Christian on the census form 54% believe in a personal God, 10% don’t believe in a god, but think there is some sort of supernatural intelligence out there, 22% believe in God as being the laws of nature or the cause of the universe, 6% don’t believe in any sort of God.

– Q11 asked people who put Christian on the census form to define their religious views – 30% said they had strong religious beliefs and were Christian, 48% said they did not have strong religious beliefs, but thought of themselves as Christian or had been brought up to do so, 12% didn’t consider themselves religious at all, 8% thought they were spiritual rather than religious. Further on a question asks directly if people consider themselves to be religious or not – 45% say they do, 50% say they do not.

– Q24 & Q25 asked about some of the core beliefs of Christianity – Jesus being the son of God who was resurrected after being crucified. 32% believed in Jesus’s physical resurrection, 39% that he was resurrected spiritually but not physically, 18% that he wasn’t resurrected at all. 44% believed that Jesus was the Son of God, 32% that he was a good role model, 13% that he was just a man. Again, percentages are of people who put Christian on the census form, not the GB population overall.

Exactly how one defines what constitutes a Christian is an unanswerable question – you may equally well define being Christian as what people believe or by how they define themselves. What we can say with some certainty is that a fair proportion of people who put Christian on the census form don’t believe in a personal God, don’t consider themselves to be religious or don’t believe in some of the core tenets of Christianity.

This means that while there are other interesting questions on the poll, one can’t really use them to say X percentage of British Christians think this or that, because it is impossible to define British Christians. If one defines them as people who put Christian on the census form then you’d find only 54% believe in a personal God. If you define them as people who attend church at least once a month I expect you’d find the vast majority believe in a personal God. This is the difficulty of saying anything about ill-defined populations.

At the end of the day a lot of the survey and the PR around it seems to be aimed at knocking down the strawman argument that all those who put Christian on the census are devout, church attending, bible believing Christians when it is fairly clear from the outset that they are not. That’s not to say that the strawman argument of 72% of people are Christians so you should do this hasn’t actually cropped up in the political debate before – it has, and I’m sure it will continue to do so in the future.