John Allen Paulos, in Irreligion, thinks the Fine-Tuning Argumnt for the Existence of God fails. Unfortunately, he devotes only a few pages to this argument. And, he presents a weak version of the argument which he then thinks he has defeated.
Paulos formulates the argument as follows:
1. The values of physical constants, the matter-antimatter imbalance, and various other laws are necessary for human beings to exist.
2. Human beings exist.
3. The physics must have been fine-tuned to the constants’ values to make us possible.
4. Therefore the fine-tuner, God, exists.
Paulos then writes: “Clearly the jump from Assumptions 1 and 2 to 3 in the argument sketched above is one of the weakest aspects of this argument. What does follow from Assumptions 1 and 2 above is simply that the values of the constants are what they are.” (28)
OK. Except, as with Paulos’s attack on the cosmological argument, he again fails to present the stronger version.
In my philosophy of religion classes, using Pojman’s Philosophy of Religion: An Anthology, we discuss the essay by Robin Collins. Collins formulates the Fine-Tuning Argument as follows:
5. The existence of the fine-tuning is not improbable under theism.
6. The existence of the fine-tuning is very improbable under the theistic single-universe hypothesis.
7. Conclusion: From premises (1) and (2) and the prime principle of confirmation, it follows that the fine-tuning data provide strong evidence to favor the design hypothesis over the atheistic single-universe hypothesis.
Collins’s prime principle of confirmation is: “Whenever we are considering two competing hypotheses, an observation counts as evidence in favor of the hypothesis under which the observation has the highest probability (or is the least improbable).”
Using this argument Collins points out that the anthropic principle objection does not apply. Collins’s formulation simply concludes: “Our existence as embodied, intelligent beings is extremely unlikely under the atheistic single-universe hypothesis (since our existence requires fine-tuning), but not improbable under theism. Then, we simply apply the prime principle of confirmation to draw the conclusion that our existence strongly confirms theism over the atheistic single-universe hypothesis.
Collins cites philosopher John Leslie. Leslie uses a “firing squad” analogy and says that, if fifty sharpshooters all miss me, the response “If they had not missed me I wouldn’t be here to consider the fact” is not adequate.
Paulos also gives one sentence to the multiverse theory as an objection to the fine-tuning argument. Collins responds in detail to this objection in the Pojman essay. For one example of problems with the multiverse theory see the article by Paul Davies here.
So I think Paulos has failed to defeat the fine-tuning argument. Or, perhaps, he has defeated a certain version of it, one which I don't teach in my philosophy classes.
One more thing (I can't resist) - Paulos asks, "Why does solemnity tend to infect almost all discussions of religion." (25) Well..., it doesn't. As someone who discusses a lot of religious things with both the religious and the irreligious, I can't relate to this. It's certainly not been my experience. Paulos writes: "The incongruity necessary for appreciating humor is only recognizable with an open mind and fresh perspective." Huh? I'll have to think about that one.
