Background Probability

The Agnostic Popular Front has moved to its new home at Skeptic Ink, and will henceforth be known as Background Probability. Despite the relocation and rebranding, we will continue to spew the same low-fidelity high-quality bullshit that you've come to expect.

Friday, April 17, 2009

Contra Craig #2 - Universal fine-tuning

I’m going to try to be as charitable as possible on this argument, but it this is how it seems to go:

  1. The universe is such that it allows for the gradual evolution of intelligent life under certain circumstances

  2. It could have turned out any number of other ways, almost all of which would not have allowed for such life

  3. The best explanation for this particular universe is that an intelligent transcendent creator finely-tuned it for life

  4. Therefore, an intelligent transcendent creator of the cosmos exists. QED.

I will admit that such an argument has a certain intuitive appeal, but only the first of its three premises are well-established. The second premise has been cast into serious doubt by professional cosmologists such as Victor Stenger, but it should not take a Ph.D. in physics to see that the third premise is quite problematic in and of itself. To illustrate why, consider an argument about the conditions that prevail on our own planet:

1.  Earth is such that it allowed for the gradual evolution of intelligent life under certain circumstances

2.  It could have turned out any number of other ways, almost all of which would not have allowed for such life

3.  The best explanation for this particular planet is that an intelligent transcendent creator finely-tuned it for life

4.  Therefore, an intelligent transcendent creator of the Earth exists. QED.

When you get to premise three, you should wonder whether other planets exist which might be similarly situated to our own. In the age of Sagan, Asimov and Rodenberry this is not a particularly great stretch of the imagination. Only a few hundred years ago, though, this second argument would have seemed perfectly plausible to W.L. Craig’s philosophical and theological forebears, who forbade the possibility of multiple worlds (sometimes on pain of death) and generally preferred the view that the Earth was uniquely created for humankind.

Suppose we consider only two rival hypotheses (a) metaphysical naturalism and (b) classical theism, excluding other possibilities for the sake of convenience. Given that living being exist (who are just intelligent enough to have thoughtful debates about metaphysics) the crucial question here is which of these hypotheses best explains the fact that the universe allows for the natural evolution and sustainment of intelligent life.

It should be clear that if intelligent minds exist and metaphysical naturalism is true, it is absolutely necessary that the laws of nature are such as to allow for the natural evolution and sustainment of intelligent life. By contrast, if classical theism is true, then minds can exist as souls apart from bodies, and there is therefore no need to posit a natural world which allows for life to emerge and flourish naturally over vast stretches of time and space. If God wants intelligent beings, He may readily create as many angels and demons as he pleases, endow them with free will.  He need never give a thought to the idea of mucking about with matter, much less minds made of meat. There simply is no need for such onerous fine-tuning, if theism is assumed to be true.


2 comments:

Nathan Richmond said...

Lets say I flip a coin 100 times and record the outcome. The odds of any possible outcome is (1/2)^100, right. Thats a crazy improbable number right? Yet the result occurs. Doesn't the probabilty really only have significance before the event, when one knows the event occured?

So to me this logic of quoting the improbability of us existing is a problem that guided purposed intellegent design has.

Damion said...

Doesn't the probabilty really only have significance before the event, when one knows the event occurred?I doubt it. Suppose you know that at least one two-headed coin exists in the house, and you flip heads 100x in a row. Now, the Bayesian formulas will tell you that you can be fairly confidant that you pulled the trick coin, even if you drew your coin at random from a fairly large pile.

The trick, if course, it to specific the alternate hypothesis being tested in a way that is susceptible of quantification.