Sunday, April 28, 2013

William Lane Craig versus Rosenberg (part 4)

My series on the February 2013 debate between William Lane Craig and Alex Rosenberg:
  1. The Leibnizian Cosmological Argument
  2. The Kalam Cosmological Argument
  3. The Fine-Tuning of the Universe for Intelligent Life
  4. Objective Moral Values and Duties in the World
  5. The Historical Facts about Jesus of Nazareth
  6. God can be Personally Known and Experienced
  7. Arguments Against Naturalism
  8. The Argument from Evil
  9. Wrap-Up
Introduction

In February 2013 atheist philosopher Alex Rosenberg debated Christian philosopher William Lane Craig over whether faith in God is reasonable (debate begins at around17:14). I’ve mentioned before the reason why William Lane Craig wins debates, and since this debate is a good example of how not to debate William Lane Craig, I have been going through some of what Rosenberg did wrong and how he could have done a lot better. One happy benefit from this is that in so doing I’ll also be refuting William Lane Craig’s arguments. In this entry I’ll address Craig’s fine-tuning argument.

The Fine-Tuning of the Universe for Intelligent Life

Craig’s fine-tuning argument in the debate goes as follows:

  1. The fine-tuning is due to either physical necessity, chance, or design.
  2. It is not due to physical necessity or chance.
  3. Therefore, it is due to design.

What Rosenberg did

Rosenberg gives his rebuttal to this at around 45:34. Rosenberg says it would be “carbon chauvinism” (at around 46:05) to think that life couldn’t have evolved under different constants and quantities; perhaps different elements, such as germanium or silicon, could have done the job. While stuff like silicon-based life is popular in science fiction, there is reason to believe it is merely science fiction. To quote Stephen Hawking and Leonard Mlodinow in page 157 their book The Grand Design

Though one might imagine “living” organisms such as intelligent computers produced from other elements, such as silicon, it is doubtful that life could have spontaneously evolved in the absence of carbon. The reasons for that of technical but have to do with the unique manner in which carbon bonds with other elements.

Craig didn’t respond this way in the debate (though he has in the past noted that silicon-based life wouldn’t work), but he took a different approach this time. Craig claimed is that not even matter or chemistry would have existed without certain fine-tuned conditions (1:10:10). Rosenberg had no reply to this.

One of Rosenberg’s rebuttals is the possibility (around 46:57) of the world ensemble explanation being true, where there are many universes with randomly varying constants and quantities to the point where it is probable that at least one of them would permit life. But in his opening statement (i.e. the first time he got up to speak) Craig says that

the odds of a life-permitting universe governed by our laws of nature are just so infinitesimal that they cannot be reasonably faced. Therefore the proponents of chance have been forced to postulate the existence of a world ensemble of other universes, preferably infinite in number and randomly ordered, so that life-permitting universes would appear by chance somewhere in the ensemble. Not only is this hypothesis to borrow Richard Dawkins’s phrase “An unparsimonious extravagance,” but it faces an insuperable objection. By far, most of the observable universes in a world ensemble would be a world in which a single brain fluctuates into existence out of the vacuum and observes its otherwise empty world. Thus if our world were just a random member of a world ensemble, we ought to be having observations like that. Since we don’t, that strongly disconfirms the world ensemble hypothesis, so chance is also not a good explanation.

Craig said this before Rosenberg gave his world ensemble response, and he had no rebuttal at all to what Craig said here.

What Rosenberg should have done

Craig says:
Physical necessity is not, however, a plausible explanation because the finely-tuned constants and quantities are independent of the laws of nature. Therefore, they are not physically necessary.

Suppose it’s true that there is no physical necessity that we are at this moment aware of that controls the constants and quantities being what they are. How does this show that there isn’t any such physical necessity? Since we are far more intimately aware of physical necessities and have no experience with magical deities, why shouldn’t we posit a hitherto unknown variety of physical necessity and favor this explanation over a hitherto unknown magical deity designing the universe? Rosenberg could have brought up this objection, but instead he raised an objection that Craig already addressed.