Wednesday, 25 April 2018

Naturalism or Preternaturalism?



"Dream Vision" by Albrecht Dürer, 1525.*

Naturalism in philosophy is (roughly) the view that the structure and behaviour of the universe is governed by natural—not supernatural—laws. Many naturalist philosophers also hold the view that science is the best means for investigating the nature of reality, including the reality of consciousness. Others would point out that many contemporary perplexities are not due to a lack of scientific evidence or insight but are instead the result of various conceptual errors over which science has no jurisdiction. After all, we don’t look to science to adjudicate on questions of logic. Sense is not science.

I’m a member of a Facebook discussion group on the subject of naturalism. The group is managed by Tom Clark, who also runs a website by the same name (naturalism.org). In an article about lucid dreaming, Clark writes: “As people learn about lucid dreaming, an interesting fact about the brain will become known: it is a virtual reality generator. But an even more remarkable fact is waiting in the wings: waking experience is virtual reality too.”

Like Clark, I sometimes have lucid dreams, but unlike him, I don’t regard these as evidence that “the brain constructs a conscious phenomenal world”. Clark’s view is very similar to what is known as “mind-body dualism”, since it seeks to explain the relation between mind and matter by way of supernatural, or in Clark’s case preternatural, powers. I hope it is clear that even a preternatural explanation conflicts significantly with the aims and commitments of naturalism. This post is a very brief attempt to bring this conflict into relief.

Across the natural world, many organisms have developed deceptive strategies that aid their survival. Camouflage is just one example of this evolutionary achievement. Dissimulation is another. It might not be obvious, but all forms of deception exploit various weaknesses, whether these be perceptual weaknesses or weaknesses of knowledge or understanding. This raises a very serious problem for Clark, because in order to generate any form of virtual reality, the brain would have to exploit some form of weakness, constraint or limitation on the part of the consumer/victim/user. In the competitive context of organismic life, there is something to be gained from deceiving potential predators or prey. But in the case of the internal organs like the brain, the advantages are obscure. Organs obviously don’t prey on other parts of an organism and nor can they exploit anything or be exploited in any way that isn’t to the advantage or detriment of the organism as a whole. So from this evolutionary perspective, Clark’s dualistic claims simply do not stack up.

Clark repeatedly uses terms like “generates”, “constructs”, “builds”, “models” and “represents” to characterise the alleged creative abilities of the brain. When we speak of a gust of wind creating a mess or a tsunami creating destruction we do not suppose that the wind or sea are creators. Clark’s use of these terms, on the other hand, invokes a very different sense of “creation”; a sense that is little different from the supernatural explanations that naturalism ordinarily seeks to avoid.

What is true of terms like generation, construction, creation etc. is also true of action in general: 

When we describe a wheel as rotating, a ball as rolling downhill, water as flowing, a pendulum as swinging back and forth, a ship as steaming ahead, we are not describing them either as acting or as acting on anything. We are merely describing what they are doing. (Hacker 2010, p.144. Original emphasis)
Brains certainly do things in the same way that other inanimate objects do things, but any actions brains are involved in are actions of the organism as a whole. No organ, not even a brain, can take action on its own behalf. This is why we rightly regard brains as integral to the organisms of which they are parts. It makes no sense to treat brains as autonomous agents with their own generative powers.

Naturalism usually takes the view that explanations should seek to make as few assumptions as possible. But the virtual reality hypothesis requires an order of complexity, coherence, organization and generative action far beyond anything found in the natural world. In fact it is far beyond anything found in the cultural world either. The assumption that brains are devious creators is almost as extravagant and implausible as it is possible to get. Only an omniscient deity would be a more unlikely neural puppet master.



*Dürer's text reads: "In 1525, during the night between Wednesday and Thursday after Whitsuntide, I had this vision in my sleep, and saw how many great waters fell from heaven. The first struck the ground about four miles away from me with such a terrible force, enormous noise and splashing that it drowned the entire countryside. I was so greatly shocked at this that I awoke before the cloudburst. And the ensuing downpour was huge. Some of the waters fell some distance away and some close by. And they came from such a height that they seemed to fall at an equally slow pace. But the very first water that hit the ground so suddenly had fallen at such velocity, and was accompanied by wind and roaring so frightening, that when I awoke my whole body trembled and I could not recover for a long time. When I arose in the morning, I painted the above as I had seen it. May the Lord turn all things to the best."

Long before making this image, Dürer wrote: "How often do I see great art in my sleep, but on waking cannot recall it; as soon as I awake, my memory forgets it."