Steven Dutch: Hume ja Älykäs suunnittelu

David Hume kuuluu länsimaisen sivilisaation suurten nerojen joukkoon. Niinpä kun sanotaan, että Hume on jo 200-vuotta sitten kumonnut näkemyksen luonnossa näkyvästä älykkäästä suunnittelusta (Argument of Design), väite herättää kunnioitusta ja sulkee monet suut tieteen temppeleiden pylväiköissä.

Professori Matti Leisola mainitsee jossain, kuinka erään yliopiston rehtori torjui keskustelun ID aiheesta juuri viitaten "David Humeen ja Immanuel Kantiin, jotka ovat älykkään suunnitelun ajatuksen kumonneet".

Geologian emeritusprofessori Steven Dutch,  Wisconsin Yliopistosta ei hämmentynyt väitteestä, vaan  lähti katsomaan, mistä oikein on kyse. Dutch on julkaissut verkossa luentoaineistoaan pseudotieteistä, jossa hän tutkii David Humen teosta Dialogues Concerning Natural Religion (1776). Siitä tähän joitain poimintoja.


Keskustelijat ja teema
Teoksen "dialogi" on itse asiassa kolmen kuvitellun henkilön keskustelua

Demea ...main role is to pose arguments that the other two players can demolish, or to ask questions that give the other two characters opportunities to elaborate their positions. He believes God is so unknowable and inscrutable that any effort by humans to describe God borders on sacrilege by assigning to God the limited and corrupt attributes of human beings.

Philo is the hard-headed skeptic who sees paradoxes and inconsistencies in every line of argument, sees alternate interpretations for every observation, and who thus essentially believes nothing can be known for certain. His arguments are most nearly those of the modern skeptic. Hume at times lets him go over the top and express extreme ideas, which are then tempered a bit for the sake of more sensitive readers.

Cleanthes is the pragmatic skeptic, who is keenly aware of the limitations of logic and observation but who nevertheless believes our mental picture of sense impressions and logical inferences is too real to dismiss entirely. It is Cleanthes who articulates the Argument From Design.

"Natural Religion" refers to what can be known of God from wholly natural phenomena, not preconditioned by prior beliefs or influenced by revelation.

Yhteenveto Humen argumenteista suunnittelua vastaan

• We cannot validly reason from earthly parallels to the Universe as a whole.
• Since the creation of the universe was a unique event, we cannot say anything about it.
• The order in nature could equally well result from the intrinsic properties of matter itself.
• The existence of pain and suffering cast serious doubt on the existence of a benevolent Intelligence.

Radikaali skeptikko Philo voittaa keskustelun, mutta Dutch muistuttaa, että kahden muun keskustelijan kaatuvat argumentit eivät välttämättä osoita, että Philon argumentit pitäisivät paikkansa. Niitä on arvioitava niiden oman painoarvon mukaan.

Tiede on kehittynyt Humen ajoista

1. In Hume's day, the only rigorously known scientific laws were gravitation and Newton's laws of motion. The fact that these had successfully explained the motions of the planets had profoundly impressed all of society. Also, Newton had successfully explained why Kepler's empirical laws of planetary motion worked, and even made a correction to them. ... Hume's trio was restricted to finding order in nature solely in the complex phenomena of the natural world, something that might not be the case today.

2. In Hume's day the stars were considered so inconceivably remote that it seemed impossible ever to have any real knowledge of them. Double stars, where one star orbits another, would be the first direct demonstration that gravitation applied among the stars. ... So we can forgive Hume for not envisioning how deeply we would be able to test the hypothesis that the laws of nature are the same everywhere. Nevertheless, Philo's argument that we cannot reason from earthly examples to the universe as a whole is flatly, definitively, wrong.

3. ... Hume could have Philo argue (Part VIII) "In all instances we have ever seen, ideas are copied from real objects...You reverse this order and give thought the precedence." The idea of conceiving something totally new and making it happen, the essence of modern technology, is completely opposite to the mental processes of Hume's time. We can forgive Hume for not foreseeing the extent to which abstract thought could precede the creation of objects, but again Philo's argument is flatly, definitively, wrong.

Humen kehäpäättelyä

The issue to be decided is whether the order in nature is the result of intelligent design. If it is, then the properties of matter (the color, luster and density of gold, for example) are also the result of intelligent design. 

Postulating a dichotomy between intelligent design and the properties of matter therefore amounts to postulating a priori that there is no design in nature. Hume (and all who follow him) essentially follow a grand circularity:

• Matter and the laws of nature are defined a priori to be separate from any intelligent design.
• Order in nature is shown to be the result of the laws of nature and the properties of matter
• Therefore order in nature is not the result of intelligent design

Nowhere is the circularity more blatant than Jacques Monod's Chance and Necessity. Monod starts by asking what criteria one would use for deciding something was intelligently designed and defines two criteria: repetition and geometric regularity. But, he hastens to add, these criteria apply only at the microscopic level. The distinction is entirely ad hoc because, if we applied it at the microscopic level, the Argument from Design would follow automatically. 

In any case, the distinction is nonsense, since macroscopic non-biological structures like crystals, cloud patterns and orbital resonances in the Solar System display repetition and geometric regularity, and microscopic structures like computer chips are of clearly intelligent origin (the bug in the first Pentium chip notwithstanding).

Olemassaolon ristiriitainen kuvaus

There's probably no greater lacuna in Hume's reasoning than in Part IX. Demea asks why there should be something rather than nothing, and why the universe we know instead of something else. By definition there can be no external cause, hence the only explanation is a logically necessary Being who "carries the Reason of his existence in himself, and who cannot be supposed not to exist without an express contradiction."

Hume puts the reply in the mouth of Cleanthes, who says it only to forestall Philo. Hume presumably assigns this role to Cleanthes to spare Philo the burden of attacking every religious doctrine and thereby alienating readers, but it's quite definite here that Cleanthes is voicing Hume's own convictions. He says:

"Nothing is demonstrable, unless the contrary implies a contradiction. Nothing, that is distinctly conceivable, implies a contradiction. Whatever we conceive as existent, we can also conceive as non-existent. There is no Being, therefore, whose non-existence implies a contradiction. Consequently there is no Being, whose existence is demonstrable."

This is essentially disproof by outright denial. We can conceive of God as non-existent, hence God cannot be logically necessary. 

Cleanthes (Hume) goes on to say that the universe might well contain hidden attributes that would make its non-existence seem as contradictory as the non-existence of God. Considering how hard Hume hammers elsewhere at the unproven nature of religious conjectures and their ad hoc nature, postulating wholly unknown properties for the universe is a nice case of the pot calling the kettle black.

...

If there is something about God that makes him logically necessary and immutable, it must be attributes we do not know, and we have no way of knowing whether the same qualities might not reside in nature. We're back to proof by postulating unknown hypothetical properties of the universe.

Hume essentially gets away with using mutually contradictory arguments by putting them in the mouths of two different characters, but nothing could be clearer than that Cleanthes, in this section, is relating Hume's ideas exactly.

Sovellutusta moderniin ID keskusteluun

Cleanthes would wonder, in turn, why it's valid to criticize theological concepts as ad hoc, while it's simultaneously permissible to postulate the existence of universes whose existence is entirely unproven and which may be forever untestable. He'd also wonder why the order in the universe is such a pressing scientific problem as to justify postulating a vast number of alternate universes but not to justify postulating an intelligent designer.

Lopuksi

Professori Dutch nostaa esiin paljon enemmän Humen ajattelusta, kuin edellä poimitut yksityiskohdat. Tekstin lukemisen jälkeen David Humen älykkään suunnittelun kumous ei enää vaikuta aivan yhtä vakuuttavalta.

Dutch toteaa, jos jokin näyttää suunnitellulta, yksi mahdollisuus on, että se todella on suunniteltu.

Moral: If something looks complex enough to be of intelligent design, one possible interpretation is always that it is of intelligent design. It may not be, but in the absence of disconfirming evidence, intelligent design is always a viable hypothesis. We can say that it's not the only possible explanation, maybe even that it's not the most likely explanation, but it's extremely hard to dismiss the idea entirely. Intelligent design is always a possible interpretation of any sufficiently complex object.

...
Toivon että nämä katkelmat auttavat hieman sinua pureutumaan Steven Dutchin monologiin David Humen kolmen hengen dialogista!

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