Skeptic Michael Shermer has an article up over at Scientific American.com on Stephen D. Unwin’s book The Probability of God: A Simple Calculation That Proves the Ultimate Truth in which he discusses how the risk management consultant out of Ohio came to the conclusion that there’s a 67% probability that God exists.
Unwin rejects most scientific attempts to prove the divine—such as the anthropic principle and intelligent design—concluding that this “is not the sort of evidence that points in either direction, for or against.” Instead he employs Bayesian probabilities, a statistical method devised by 18th-century Presbyterian minister and mathematician Reverend Thomas Bayes. Unwin begins with a 50 percent probability that God exists (because 50–50 represents “maximum ignorance”), then applies a modified Bayesian theorem.
Shermer provides a brief explanation of the formula Unwin came up with and which numbers he plugged into it and then points out the glaringly obvious reason why this little exercise is completely pointless. I’ve boldfaced the glaring error for those visitors who are a little slow on the uptake.
Plugging these figures into the above formula (in sequence, where the Pafter figure for the first computation is used for the Pbefore figure in the second computation, and so on for all six Ds), Unwin concludes: “The probability that God exists is 67%.” Remarkably, he then confesses: “This number has a subjective element since it reflects my assessment of the evidence. It isn’t as if we have calculated the value of pi for the first time.”
Shermer goes on to recalculate the formula using his own assessment of the evidence as based on his theories of “the evolutionary origins of morality and the sociocultural foundation of religious beliefs and faith” and comes up with only a 2% probability of God’s existence.
This surprising admission on Unwin’s part that the numbers he chose for the calculation are completely subjective has in no way dampened the exposure this book has received throughout the news media and more than a few True Believers™ have sent me links to the book in hopes of showing me how wrong I am to be an atheist. Truth is, there’s nothing in Unwin’s formula or book that’s likely to convince anyone who isn’t already a believer that he’s got it right. Still, there’s plenty of people out there who are making lots of money selling books that claim to offer scientific proof of God which will continue to be popular with the folks who have trouble accepting the idea of God purely on faith.
I’ve had my own brush with this sort of thing in the past back when I was working as a Desktop Publishing Consultant for a local Kinko’s Copies store. There was this local fellow in his late 60’s or early 70’s who’d come into the store from time to time to have me make custom business cards and brochures for him. This fellow needed these things in order to publicize his discovery of the proof of God via a very complex mathematical formula he had concocted that was printed on the back of his business cards and was the focus of the overview in the brochures. Every time he’d come in to have me do some work he’d wait patiently while I added whatever he wanted to the cards or brochures and he’d explain, every time, in great detail, just what each X or Y on the formula stood for and how when you plugged in all the numbers and calculated it out it ended up equaling the number 1, which is God according to this guy, and therefore is proof that God exists. Some of the numbers were things such as the speed of light or the acceleration of gravity or some other well known scientific number and others were, as near as I could tell, complete arbitrary assignments he pulled out of his ass, but when you worked it all out via his formula it did come out to the number 1.
He was quite proud of this bit of mathematical mumbo jumbo and yet very concerned that not many people took him seriously on it. Well known scientists in particular, he’d often lament, would rarely respond to his letters describing his discovery and the few that did had left him feeling as though he was being humored. I was guilty of humoring him myself for the simple reason that I wasn’t in a position that allowed me to engage him in a discussion on the issue without risking my employment. Even if I had been I don’t know that I would have bothered as although he was a bit of a loon in this one regard, he was largely pleasant and harmless. With the level of belief he had invested in his idea and at the age he was all I would have accomplished in challenging him on it would’ve been to piss him off so there wasn’t much point. He was a classic victim of the Henrietta Syndrome.