May 29, 2010

From Paley to Hawking: Design and the Anthropic Principle

Hi, I hope everyone is enjoying their Saturday and is looking forward to some light weekend reading (turned out to be not so light...) as I finish a trilogy of posts on probability. This post will be a summation of the arguments of William Paley, and its modern portrayal by Dinesh D'Souza which I am taking from his debate with Daniel Dennett. They are just two people in a long line that look at the universe and see design in the universe.

I was going to sum up William Paley in my own words, but the Sanford Encyclopedia of Philosophy did a fine job in doing that for me. Paley's argument from design is,

"In crossing a heath, suppose I pitched my foot against a stone and were asked how the stone came to be there, I might possibly answer that for anything I knew to the contrary it had lain there forever; nor would it, perhaps, be very easy to show the absurdity of this answer. But suppose I had found a watch upon the ground, and it should be inquired how the watch happened to be in that place. I should hardly think of the answer which I had before given, that for anything I knew the watch might have always been there. Yet why should not this answer serve for the watch as well as for the stone? Why is it not as admissible in the second case as in the first? For this reason, and for no other, namely, that when we come to inspect the watch, we perceive—what we could not discover in the stone—that its several parts are framed and put together for a purpose … [The requisite] mechanism being observed … the inference we think is inevitable, that the watch must have had a maker. Every observation which was made in our first chapter concerning the watch may be repeated with strict propriety concerning the eye, concerning animals, concerning plants, concerning, indeed, all the organized parts of the works of nature. … [T]he eye … would be alone sufficient to support the conclusion which we draw from it, as to the necessity of an intelligent Creator..."

Paley is looking around the world and seeing complex things, that appear to work together to have a purpose and so he generates a view that is not outlandish, yet still doesn't hold up pasted even cursory scrutiny now. In minutes the information about the transitional states of the eye can be found, from going to simple cells being able to detect light to the eyes we have today. Two good pages for this information I found was The evolution of the mollusc eye and a15 minute video of  Richard Dawkins' explanation. This can be done just as easily to show the natural design of Birds, Whales, or even the bacterial flagellum. The designs also have major flaws that a conscious designer wouldn't include, like the vestigial legs in whales, wings in some beetles, or the blind spot in the human eye. That's right there is a blind spot that can easily be demonstrated in both your eyes. This would be enough to argue agianst Paley, but the argument from design also looks at the nature of the universe and sees design there as well.

Dinesh references Stephen Hawking and his book A Brief History of Time. The area he references is between pages 126-131, where the anthropic principle is brought up. It is shown that there are many different values that could exist for the laws of physics as we know them today, and the example of the electric charge of an electron is given. If the charge of the electron was only slightly different, stars either wouldn't have been able to burn hydrogen and helium, or else they would not have exploded. Hawking goes so far to say that,

"This means [The initial rate of expansion of the universe having to be carefully chosen] that the initial state of the universe must have been very carefully chosen indeed if the hot big bang model was correct right back to the beginning of time. It would be very difficult to explain why the universe should have begun in just this way, except as the act of a God who intended to create beings like us."

Hawking is only able to do this because he first completely writes off the 'strong anthropic principle' for two reasons. He defines the strong anthropic principle as a belief that either there are many different universes or many different regions of a single universe. The first reason he states agianst is questioning in what sense those universes exist. The fact that there are no interactions between universes means we can use the principle of economy and cut them out.

This is something I find a little troubling, because when he left the realm of out universe and started talking about the creation of the universe before the big bang or during the big bang at a level where physics doesn't work he really left the realm of science and entered the realm of philosophy and speculation. It is fine to write off other universes (some physicists might disagree) as a scientific notion, just as God can be written off in a scientific sense until there is some empirical evidence for either, but he can't rule out either option when speculating. 

There is also an objection be to had with Hawking's use of the principle of Economy. I am of the same opinion as Karl Popper when he says that,

"My point is that only after recognising the plurality of what there is in this world can we seriously begin to apply Ockham's razor. To invert a beautiful formulation of Quine's, only if Plato's beard is sufficiently tough, and tangled by many entities, can it be worth our while to use Ockham's razor. That the razor's edge will be dulled in being used for this tough job is only to be expected. The job will no doubt be painful. But it is all in a day's work."

The principle of economy, principle of parsimony, or Ockham's razor shouldn't be used to dismiss a theory or idea out of hand, which Hawking is clearly guilty of. The theory may be dismissed as something that can't explain the physics of the start of the universe, but when he moves into the realm of speculation, especially in an area where empirical evidence cannot be given, a theory cannot be written off by the pure lack of evidence.

The second reason is that is that the strong anthropic principle would claim that it would mean this whole vast construction he here for our sake and that idea would be very hard to believe and this leave Hawking believing either there are unified principles that created the universe or there was something that tuned those physical laws. Hawking evidently believes the former rather than the latter.

This is also overstated, by Hawking. If there are multiple universes with different physical laws, saying that this universe is fine tuned for humanity is akin to saying that this universe has the physical laws needed for human life to evolve. Just because there are multiple universes and this is the universe we specifically evolved doesn't necessarily entail that this universe was specially created for us. Hawking is jumping to a conclusion that I think few people would make. His 'weak anthropic principle' (which he agrees with) is really just the same as his 'strong anthropic principle' except there seems to be more bias in how he describes the stronger principle and he likes to talk about multiple universes in the strong one.

The universe does have some constants that if changed would make life as we know it impossible. This doesn't mean that God has to be postulated as the answer as Paley and Dinesh would have you believe. The physics of the universe may be completely improbable, but so is every dealing of 52 cards. When you look at something after the fact and judge the probability it is in one sense unfair (When you account for the whole context it makes anything improbable) or in another sense non-existent. The probability of the universe having the physics we have is 100%, it has already happened. Life must exist in a place where life is possible to exist by necessity. To answer why life is here or what created the big bang right now are areas that we can honestly just say, "I don't know"  and there is nothing wrong with that.

As always this was longer and more technical then I hoped it would be, so thanks for those of you who made it through it. I also only deal with the anthropic principle as defined by Hawking, so there is no need to postulate other definitions. I like Chomsky's idea of letting who you are talking about create the definitions, as it creates both understanding and fairness. Anyway, thanks for reading.

-The Moral Skeptic


  1. Now if I can only get the message across to the religious people I usually have to interact with. No matter how I try to simplify the concept they just nod their heads and go "yes, but how do you explain the complexity of life and how the universe is made to sustain it?"
    I swear, some days I don't even bother.

  2. Yeah, I agree..and my next post will be on true belief...and it pretty much echo's your sentiment.