Monday, July 30, 2007

Teleology in medical science

Richard Dawkins is often commended for his mastery of the English language. Actually, the English are ordinarily commended for their mastery of ironic understatement, but understatement is hardly a prominent feature of Dawkins’ prose style, especially when attacking Christian theism.

For example, Dawkins has characterized intelligent design theory as a “lazy cop-out” and a “Get Out Of Jail Free card.” To flesh this out, let’s consider Daniel Dennett’s threefold analysis:

“According to Daniel Dennett, there are three different strategies that we might use when confronted with objects or systems: the physical stance, the design stance, and the intentional stance.”

“When we make a prediction from the design stance, we assume that the entity in question has been designed in a certain way, and we predict that the entity will thus behave as designed… Design stance predictions are riskier than physical stance predictions. Predictions made from the design stance rest on at least two assumptions: first, that the entity in question is designed as it is assumed to be; and second, the entity will perform as it is designed without malfunctioning.”

“The sorts of entities so far discussed in relation to design-stance predictions have been artifacts, but the design stance also works well when it comes to living things and their parts. For example, even without any understanding of the biology and chemistry underlying anatomy we can nonetheless predict that a heart will pump blood throughout the body of a living thing. The adoption of the design stance supports this prediction; that is what hearts are supposed to do (i.e., what nature has ‘designed’ them to do).”

“As already noted, we often gain predictive power when moving from the physical stance to the design stance. Often, we can improve our predictions yet further by adopting the intentional stance. When making predictions from this stance, we interpret the behavior of the entity in question by treating it as a rational agent whose behavior is governed by intentional states. (Intentional states are mental states such as beliefs and desires which have the property of ‘aboutness,’ that is, they are about, or directed at, objects or states of affairs in the world.”

Of course, Dennett doesn’t believe that natural objects were designed to do anything in particular. He simply regards the design stance as well as the intentional stance as a useful fiction.

From a Christian standpoint, we can take this literally. Natural objects were designed by God.

And we can attribute an intentional state even to a natural object that has no mental states in the indirect sense that it exemplifies divine intentionality—like a remote control toy airplane that goes wherever it’s directed to fly.

There is a deeply entrenched tradition within modern science of banning teleological explanations from nature. I’m going to quote some observations by a modern philosopher, and then discuss the repercussions were we to carry the denial of natural teleology to its logical denouement.

“The tension between religion and intellectual knowledge definitely comes to the fore wherever rational, empirical knowledge has consistently worked through to the disenchantment of the world and its transformation into a causal mechanism. For then science encounters the claims of the ethical postulate that the world is a God-ordained, and hence somehow meaningfully and ethically oriented cosmos,” D. Owens, “Disenchantment,” L. Antony, ed. Philosophers Without Gods (Oxford 2007), 165.

“My worry is that the truth of science would not be liberating. To empower, science must extend our ability to act; yet by draining the cosmos of meaning or purpose, science threatens to undermine this very capacity. And this should make us wonder if we can live in a disenchanted world. Religious worldviews may not be true, but we may not be able to do without them unless we can find some other way of imbuing the cosmos with meaning,” ibid. 165-66.

“There are other nonscientific beliefs that stop our using technology without questioning its power. Say there is an ancient oak in my garden, in just the place I would like to build a little crazy golf course for the kids. I decide to cut the oak down with my chainsaw. Many of us would have qualms about this, but not because we have any doubts about the reliability of the chainsaw. Wouldn’t it be wrong to cut down such a magnificent tree just to build a crazy golf course? We might think this wrong because other people, my neighbors and future generations, would be deprived of the sight of this grand old tree. But, some say, it is wrong to destroy this tree for a quite different reason, a reason that has nothing to do with the interests of human beings, present or future. In their view, living things like an oak have a certain place in the natural order. They grow leaves, produce acorns, and become gnarled. In so doing, they discharge their natural function. We have no right to interfere with the natural functioning of the oak just because we want another crazy golf course. We have no right to frustrate the aims implicit in the oak’s activities and terminate its existence. To cut the oak down and burn it in order to make way for a crazy gold course would be to misuse that bit of nature, to pervert its natural functioning. Here, the application of technology must be curbed,” ibid. 167.

“There is nothing in the scientific picture of the world to support this line of thought. The scientist acknowledges that we human beings have purposes and we impose those purposes on the world: we fix our environment to suit ourselves. But the things we work on, our physical material, has no purpose of its own. I may make some sticks of wood into a chair and thus give them a function. But, apart from me, these sticks have no function. They could be used as a seat, as a doorstop, or as a bludgeon. Anything these sticks can do I could use them to do and that would become their function. It is people who determine what parts of the natural world are for: in themselves they have no purpose,” ibid. 167.

“Oaks, like all other species of living things, are not designed; rather they are a product of random mutation and natural selection…There is nothing here to support the idea that the tree’s shedding its acorns is a more natural event than my applying a chainsaw to its trunk,” ibid. 167-68.

“When I speak of science’s disenchantment of the world, I mean science’s removal of natural purposes and meaning from the world…Science’s powers of disenchantment now affect our understanding of human beings themselves. It is our turn to be disenchanted,” ibid. 168.

“We must drop this talk of ‘natural’ and ‘unnatural’ where the human body is concerned. The body is a machine that is there to serve our purposes. Once we know how this machine works, we can treat it just as we would our car or our house,” ibid. 169-70.

“A few years ago, I saw a television program about a man who fervently wished to be rid of his healthy left leg: this leg was a part of his body he simply did not want to have. His left leg felt like an imposition, an encumbrance, even a deformity. The man’s misery was clearly genuine, and we watched him search desperately for a surgeon willing to amputate. Unsurprisingly, all the doctors he approached turned him down,” ibid. 171.

“The doctors refused this man because, they thought, a doctor’s job is to make people healthy, not to give them whatever they want. It was not biochemistry, physiology, or anatomy that taught them this. These sciences explain only how human bodies actually work and how they came to exist. Evolutionary biology no more prevents doctors from cutting off a man’s leg to make him happy than it forbids me to cut down the ancient oak in my garden because it makes me happy. What we ought and ought not do with the human body is beyond science’s scope…Is such thinking mere superstition, a harmful vestige of a prescientific age we should have outgrown long ago?” ibid. 171.

Now for three more comments:

i) Owens says that “we human beings have purposes and we impose those purposes on the world.”

But eliminative materialism has extended the program of disenchanting the world to disenchanting the human mind. It denies intentional states to the human mind. We are not goal-oriented creatures.

ii) Suppose we were to consistently apply the denial of teleological explanation to medical science. Owens already touched on that point, but his argument can be taken a step further.

Why do I go to the doctor? Because I feel unwell. It may be due to aches and pains that interfere with my performance. In some cases, the symptoms may be debilitating. In other cases, the symptoms may be life-threatening.

The doctor attempts to diagnose the source of the problem. He can’t fix the problem unless he can identify the problem.

But if science denies the teleological structure of natural objects, then there’s nothing to fix since nothing went wrong in the first place. Unless the brain was designed to perform a particular function, brain cancer is not a malfunction. There’s nothing to cure.

iii) Finally, notice the tension between Dawkins complaint against IDT and the denial of teleological explanation in the secular scientific method. Dawkins regards IDT as a stopgap theory. According to him it short-circuits the ultimate explanation.

But if a scientific explanation must exclude a teleological explanation, then what is there left to explain? If natural objects have no natural functions, or if they only have whatever function we artificially assign to them, then what does a scientific explanation amount to?

1 comment:

  1. On the other hand, is it possible that ID is guilty of the argument from incredulity? If I were to play devil's advocate, I might say that the ID'er believes in design and purpose in nature simply because it's impossible to conceive that the case may be otherwise - especially when it comes to examples like the Boeing 747 illustration, or the found watch. Any thoughts?