The 67% likelihood of divine order

Battiest story for a long time:

A scientist has calculated that there is a 67% chance that God exists.

Dr Stephen Unwin’s jolly idea for the calculation starts with the assumption that there is a 50/50 chance of a divine being (but which one, may I ask?), and weighs the probabilities from there, taking into account everything from the existence of evil to miracles.

The attribution of such a precise number to a matter of faith should give a clue to what’s gone wrong here.

Theology will not submit to actuarial analysis.

Unwin is making, I think, a category mistake partly due to a hope that matters of belief can be quantified. The existence of evil in the world, for instance, is only proof of God’s non-existence if you think that there is no theologically adequate answer to the problem of evil, just as the existence of complex eyes is only proof of God’s existence if you happen to be a Creationist. Likewise miracles; if you believe that all alleged miracles have a natural explanation, this offers no weighting to the proof of God’s existence (or, perhaps, should weigh againstexistence).

This can make Unwin’s theological spreadsheet a good parlour-game fun if you fancy quantifying your own position on the scale. However, to pretend that it offers even the hope of an objective answer is hopeless. (To be fair, Unwin’s book is not yet out, and I would lay a fair bet that, unlike his publisher, he is careful to make exactly this distinction.)

The notion of making such a calculation is, I think, flawed from the start. Unwin is apparently making use of Bayes’ Theorem, which would allow him to calculate the probability of a contingent event, and a future one at that. Both of these are problematic, but it should suffice to explain the problem with contingency.

The calculation starts with an assumption that there is a 50/50 chance of God’s existence. In terms of the Bayes’ calculation, this means that there is a one in two chance that God ‘will happen’.

This, I’m afraid, is the category mistake. God is not a contingent event. God is, depending on your viewpoint, a necessary and permanent fixture, or a phantasm. In other words, God is either necessary or impossible. The only contingent is the amount of certainty you, as an individual, have in either direction.