This week's edition of BBC2's popular science strand Horizon was delayed from 20 March because the Iraqi invasion was getting under way. What a lucky postponement! Maundy Thursday, which was the revised transmission date, is the day Christians commemorate the Last Supper. But what brought the diners to sit around Christ's table in the first place? According to God on the Brain, they could all have had something wrong with their temporal lobes.
The sublime highlight of the show was watching a scientist manipulate Richard Dawkins's temporal lobes in an attempt to make him believe in God, but it opened with two actual sufferers from temporal lobe epilepsy. Rudi Affolter, an atheist, described how he had come over funny in a hospital bed and became convinced that he had died and gone to hell. He had been shocked to discover that the Christian religion was the correct one all along. Gwen Tighe's experience was even more dramatic. Having given birth to her son Charles, she looked up beatifically to her husband and remarked how nice it was to be part of the Holy Family. In her eyes, you see, little Charles was little Jesus.
The epilepsy had mistakenly (there was no doubt of that) convinced them they had been touched by God. But then, asked Horizon, haven't the founders of all religions been convinced of that? Were they all epileptics then? Liz Tucker, who produced and wrote the programme, didn't actually suggest that St Paul had hit his head tripping up on the road to Damascus or that Moses got an inner-ear infection from his sodden infancy among the reeds of the Nile. But Ellen White, a founder of the Seventh-day Adventist movement (12 million believers), had, it turned out, been hit on the nose by a stone in her youth. She emerged from her coma so religious and moralistic that she went on to write 100,000 pages of mystically inspired instruction on issues as diverse as masturbation and the sin of tea-drinking.
Coincidence, you might say. Or else: to believe in God, it helps to be nuts. But it was not that simple. Professor Ramachandran from the University of California had hooked up some of these epileptics to his galvanic skin response machine and found they had reacted more strongly to cards saying "Bibles" than to cards saying "nipples". This finding, we were told, was "explosive" and had given birth to a whole new discipline: "neuro-theology".
Enter the neuro-theologian Dr Michael Persinger and his theory that the temporal lobes can be stimulated by electromagnetic fields. A bit of twiddling with our right hemisphere's electricity and any of us might feel "the sensed presence" of something Other. And it did not only occur in laboratory conditions. One kid was convinced there was a ghost in her bedroom, thanks to the weird rays being sent out by her clock radio. Colleagues, by the way, had warned Persinger off this line of work, but he was having none of it. "Experimental method is the most powerful tool we have," he said. "It is how we find truth from non-truth."
And so to Dawkins, whose deserved fame as a populariser of Darwinian theory has sadly become eclipsed by his reputation as a rentagob atheist. He was persuaded to wear a motorcycle helmet with wires poking out of it, while on the other side of the lab Persinger's team twiddled knobs - right a bit, left a bit - in an attempt to induce God in his bonce. Dawkins's right leg twitched but, sadly, that was all. "It felt," he explained, "like I was in total darkness with a helmet on my head." He was very disappointed. He had always been curious to know what it would be like to have a mystical experience. So Dr Persinger had failed to convince Dawkins, just as had "the Pope, the Archbishop of Canterbury and the Dalai Lama" (was this a three-part series I missed?).
The trouble with all this neuro-theology was that, far from sorting truth from "non-truth", it showed every indication of starting up a whole range of new squabbles. Persinger certainly wasn't going to admit his experiment had failed. We all, he insisted, sit somewhere on a scale of temporal lobe sensibility. At the top are the epileptics. At the bottom is Dawkins, and you just can't get to him.
Bishop Stephen Sykes of the University of Durham was equally unfazed. Neuro-science posed no danger, so long as Christians were "canny" in their interpretation. Even Professor Ramachandran said that our susceptibility to religious experience "may be God's way of putting an antennae in your brain to make you more receptive to God". On the other hand (sop to Dawkins), maybe there was an evolutionary advantage to religion: believers apparently live longer, are healthier and have less cancer and heart disease.
The programme was luridly shot in the manner of The X-Files, with crucifixes and floating images of brain scans; imagery all ready, I assume, for American syndication. Its script, however, was ultra-cautious, heavy with BBC balance. The conclusion seemed to be that while we are hard-wired for religion, and some are harder-wired than others, that does not mean we can dismiss God as a trick of neurocircuitry. Personally, I could not see why not - except, for "trick", I'd substitute "malfunction". But a Happy Easter to all, not least the temporal lobe epileptics out there. They have more to bear than I knew.
Andrew Billen is a staff writer on the Times