by Eric Steinhart
Every one of the standard arguments for the existence of God can be reformulated as an argument against the existence of God. Consider the Fine Tuning Argument.
The theistic version of the Fine Tuning Argument goes like this: (1) The Fine Tuning Argument is sound. (2) If the Fine Tuning Argument is sound, then there is a Tuner. (3) Therefore, there is a Tuner. (4) If the Tuner is God, then God exists. (5) The Tuner is God. (6) Consequently, God exists.
The atheistic version of the Fine Tuning Argument goes like this: (1) The Fine Tuning Argument is sound. (2) If the Fine Tuning Argument is sound, then there is a Tuner. (3) Therefore, there is a Tuner. (4) If the Tuner is not God, then God does not exist. (5) The Tuner is not God. (6) Consequently, God does not exist.
The fourth premise in the atheistic version follows from the definition of God. If God is a tuner, then God is essentially a tuner. It’s not possible for God to exist and for God to fail to be a tuner. The theist, on learning that the Tuner is not God, can’t say that God’s busy doing other things or that fine-tuning the universe falls outside of God’s job description. On the contrary, it’s part of what it means to be God.
The fifth premise is what the atheist has to justify. The atheist has to prove that the Tuner is not God. This can’t be done by just blithely saying that the Tuner might not be God. It isn’t enough to just point to some other alternative possibility. Mere possibility is not what is asked for here. The atheist has to demonstrate that the Tuner is not God.
The way to do this is to present an alternative that is clearly a better explanation for the fine tuning than God. The argument goes like this: (1) The Tuner has a feature F if and only if F is required for tuning the universe (say, for life). (2) If the Tuner were God, then the Tuner would have additional features. (3) Therefore, the Tuner is not God.
Finely-tuning universes for life doesn’t seem to be very demanding. The assumption behind all the fine tuning arguments is that tuning involves setting the values of some finite number of numerical parameters. If there are n parameters, then their value ranges are the coordinate axes of an n-dimensional space. Each point in this space has the form (v1, . . . vn). The Fine Tuning Arguments always seem to assume that these values are plugged in to some fixed system of equations E. Thus E(v1, . . . vn) is the form of some possible universe. It’s usually also assumed that the equations apply to some initial conditions. They act as an operator on the initial conditions i. Any initial condition is a member of some set of initial conditions I. So the full form of a universe is (E(v1, . . . vn))(i). This form has to be tested for life. Here’s the algorithm:
algorithm FineTuneForLife() [
for every point (v1, . . . vn) in the space (P1, . . . Pn) do [
for every i in the set of initial conditions I do [
if (the form (E(v1, . . . vn))(i) permits life),
then make a universe with that form;]]]
Either there is some machine (some computer) that can run the algorithm FineTuneForLife, or else there is not. If there is no such machine, then perhaps the Tuner is God. If there is such a machine, then the Tuner is not God. The Tuner is merely a computer. More precisely, the Tuner is the simplest machine that can run the algorithm FineTuneForLife.
I doubt that any finite state machine can run FineTuneForLife. I’m not sure that any Turing machine can run FineTuneForLife. But Turing Machines are not very impressive; there are far more powerful transfinite computers. The outer limits of computation are said by some mathematicians to be equivalent to the constructible hierarchy of sets (also known as L). If there are models of our physics that fall within the constructible hierarchy of sets (also known as L), then there is a machine that can run FineTuneForLife. So the atheist has to defend this claim: there are models of our physics that lie in L. And I think that’s a claim that is very easy to defend.
It’s worth pointing out that FineTuneForLife is a simple brute force search. There are almost certainly very powerful ways to optimize that search. More optimal searches usually require less powerful computers.
It’s also worth pointing out that human beings already know how to finely tune toy universes for artificial life. Small numbers of human beings, working for only a few decades, have already produced impressive software universes that contain life-like structures. So, how hard can it be to run something like FineTuneForLife? Does it really require an intellect whose power transcends that of every logically possible machine? The successes of artificial life suggest that fine tuning isn’t all that hard. If it can be done by a machine, then God does not exist.