Friday, January 31, 2014

Can Nature Calculate?



Philosophy was born in dialogue and perhaps consists in nothing more, even if that dialogue is sometimes internal.  I am very grateful to Miranda Flint for engaging me in these posts.  In the comments to the last post, Ms. Flint poses two significant questions. 
I’m not sure I agree with your suggestion that participating in rituals like sacrifice and circumcision is a calculated risk - calculated by natural selection. I think that these things contradict each other. If we are dealing with natural selection, then there is no calculation. By definition, calculation is “to determine or ascertain by mathematical methods” or to “determine by reasoning, common sense, or practical experience”. I don’t think nature does these things. A god or a man might.
When I said that costly signaling involves a calculated risk, I only meant to indicate that there are both costs and benefits involved and that it makes sense as a strategy only if the latter outweigh the former. 
However, I think Ms. Flint is rather stingy her extension of calculation.  I can determine the proper output of my furnace by mathematical methods but so can my thermostat.  Surely we must add calculators and other machines to the list of beings capable of calculation.  What about nature?  Allow me to suggest a thought problem.
What if you had the power to modify the design of a certain creature on a certain island, let’s say it’s a bird.  Your goal is to preserve the species.  You design the birds to feed on seeds, which are abundant.  As the seeds are very small and must be frequently picked out of rocks and crevices, you give the birds beaks shaped like tweezers: long and thin.  For a while you see that your design is good. 
Then the climate begins to change and with so does the vegetation (I haven’t granted you control over either).  You notice that the population of shrubs changes and seeds with large, thick shells begin to proliferate.  Your tweezer-beaked birds cannot crack them and their population plummets.  You calculate that what your birds need now are shorter, thicker beaks, like the blades on a pair of garden shears.  That does the trick, and your flock gradually recovers.  Such is what a calculating person, human or divine, might do to keep a population going across time.  Can nature do the same work as intentional calculation?
It manifestly does do so.  Darwin’s finches, as Peter and Rosemary Grant documented over several decades of study on one of the Galapagos Islands, require frequent adjustment.  Long periods of wet years followed by periods of dry years result in a fluctuation of beak design, as surely as if a calculating warden were constantly redesigning the birds.  As the foliage changes, the most adaptive beak design changes in response.  There is no reasonable doubt that this same force, natural selection, molds, maintains, and adjusts the traits of every living organism. 
Natural selection is not goal directed.  It is a mechanical process, just like my thermostat or the salt and water regulation in each cell of my body.  All of these things are, however, quite capable of calculation.  They are constantly calculating.  Good thing, that.  It makes it possible for creatures that do have goals, like birds and Baptists, to exist.  

I will address the second question in the next post. 

2 comments:

  1. Your thermostat cannot calculate independently. It needs man to give it its original program and therefore, I think it could be argued that man is the force that ultimately causes the calculation to happen. The same thing is true of most machines. Regarding your beak example: I think that, unless a God or man purposely changes fates, what happens in nature largely happens by accident. Birds may end up with certain beaks because of changes of nature - but is that because nature is using common sense to figure these things out - or because it is applying mathematical methods to ascertain an answer - or does this happen by chance? I will have to think about the cell argument.

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  2. Miranda: Let us stipulate that God is the ultimate cause of man. Does that mean that human beings cannot independently calculate? I say no. Likewise, the fact that human beings are the ultimate cause of my thermostat doesn't mean that it cannot independently calculate. It can and it does, so I don't have to get up at night.

    As for the beaks of Darwin's finches, no one is saying that nature purposely changes the birds. Nonetheless, their beaks are constantly fine tuned in a way that keeps those organic devices functional in a changing environment. That is how natural selection works: calculation without consciousness or purpose. Surely you are not saying that the birds are merely lucky.

    I hold, against you but with Aristotle, that chance and nature are distinct causes. What chance does it does randomly or haphazardly. Random mutations and rainy days are like that. Nature, by contrast, does things in a more or less reliable way. Water boils at the same temperature, at sea level, reliably. Cats give birth to kittens and not to catfish. Natural selection is a mechanical process but it is clearly a natural process.

    Animals calculate. One kind of spider spies for its prey from high leaves. When it acquires a target, climbs down and back up again to come around behind the victim. To do this, it has to make a mental map, as it will lose sight of the target for most of its course. Is that not calculation?

    You and I calculate, but our ability to do so depends a vast array of events that happen below the level of consciousness. While we are deliberating, our brains are alive with lightening and awash with neurotransmitting chemicals. Our conscious deliberation is the tip of an iceberg. A lot of calculation is going on beneath the surface. This doesn't mean that we are reducible to those subconscious processes; rather, it means that we emerge out of them.

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