Monday, 7 December 2009

An Inversion Of Reason To Point Out The Obvious

I've got to say I enjoy listening or reading Dan Dennett. Currently I'm pushing myself through Consciousness Explained and I've got to say it feels like he's lead me through the rabbit hole and suddenly a few pages of I've found myself in a strange reality where I have no idea what's gone on. Right or wrong, he really makes it sound so simple as if all it takes is an inversion of reasoning followed to its logical conclusion.

So looking on his university website, I came across a recent paper of his titled: "Darwin's Strange Inversion Of Reasoning". A very interesting paper seeking how Darwin's evolutionary thinking flipped the way we think about agency and structure. A watch without a watchmaker? Structure without agency? Natural selection provides the answer.

And so the argument from design dies another death. To me looking at it in the year 2009, it might now appear obvious. "Well of course it has to be that way" I can say comfortably without having to come up with the idea myself. Well the idea is out now. And no matter how many watches or houses or any other human-designed object, it just doesn't apply to animals. Why?

Think of the relationship between a watch and a watchmaker. The watchmaker puts a number of intricate and complex parts together to perform purpose. In other words, if I want a watch I need one manufactured for me. What if I wanted a puppy though? To get a puppy I go to a puppy-maker; i.e. a bitch that has given birth.

But how could this be? An intelligent agent didn't design and build me a puppy for the purpose of going for walks and throwing a ball to. Agency is involved, but it's by no means intelligent; and certainly not intelligent in the way that a human creating a robopuppy would be. If left to its own devices, the puppy would grow into a dog and then serve to start the cycle all over again. The purpose of a puppy is to make more puppies perhaps?

This argument runs into an ad infinitum, that there must be an infinite sequence of puppies going back. Yet the science shows that both the earth and the universe itself are finite. So there can't be an infinite sequence. So there was created the first dog by a magical being? Design might not have died just yet.

Life is mutable, changing over time. Dogs for example were domesticated some 15,000 years ago, and all forms of dog come from that original domesticated pack of wolves. It seems that my puppy-maker didn't always make puppies of the form I see now. Over 100 breeds and they all come from the same stock a few thousand generations ago.

So my greyhound-maker and my poodle-maker at one stage in their history made neither poodles nor greyhounds. If we follow this back, at another point it no longer made dogs. Or mammals. Or tetrapods. Or vertebrates. Or animals. Follow it back far enough and it becomes parent and eventually there's the starting point of life.


And there you have it. Back some 3.5 billion years to a pre-biotic state. The evolutionary process builds life and by the nature of the process it builds life that is adept at surviving in its environment. To posit a watchmaker is not only unnecessary, it requires a break in the process - and as David Hume would have PHILO argue, to do so on no basis of experience is speculative.

Darwin's strange inversion of reasoning allows us to reconcile the observations of how the natural world works, at the same time as explaining why there was a mismatch between such observation and our intuition to attribute structure to agency. Dawkins isn't exaggerating when he said that Darwin made it possible to be an intellectually fulfilled atheist.

2 comments:

Richard said...

The example you gave about dogs still isn't a great one. You are starting out with a particular animal and then come up with a bunch of animals that are related are only a sub-set of that original animal. You have proved very well that things change but it is a big leap to take the next stop that animal A turns in to completely new animal B.

Kel said...

It's not a big leap though. That's the point of evolutionary theory, once you have divergence and a sufficient barrier to prevent gene flow then changes will accumulate over time.

So just to ask a question about animal A turning into animal B. How would you go putting that framework into describing the emergence of birds? Because at one stage you had non-feathered non-avian dinosaurs and now we have birds that don't look very saurian at all. At what point in the sequence in the fossil record can it be shown that one is changing into another? It would seem easy enough to point at the unfeathered dinosaur as point A and at the tailless, toothless, feathered flyers as birds, but what of those intermediary stages?