Mind of a Rock...NYT

http://www.nytimes.com/2007/11/18/magazine/18wwln-lede-t.html?ref=magazine&pagewanted=print


The Way We Live Now
Mind of a Rock
By JIM HOLT
Most of us have no doubt that our fellow humans are conscious. We are also pretty sure that many animals have consciousness. Some, like the great ape species, even seem to possess self-consciousness, like us. Others, like dogs and cats and pigs, may lack a sense of self, but they certainly appear to experience inner states of pain and pleasure. About smaller creatures, like mosquitoes, we are not so sure; certainly we have few compunctions about killing them. As for plants, they obviously do not have minds, except in fairy tales. Nor do nonliving things like tables and rocks.
All that is common sense. But common sense has not always proved to be such a good guide in understanding the world. And the part of our world that is most recalcitrant to our understanding at the moment is consciousness itself. How could the electrochemical processes in the lump of gray matter that is our brain give rise to — or, even more mysteriously, be — the dazzling technicolor play of consciousness, with its transports of joy, its stabs of anguish and its stretches of mild contentment alternating with boredom? This has been called “the most important problem in the biological sciences” and even “the last frontier of science.” It engrosses the intellectual energies of a worldwide community of brain scientists, psychologists, philosophers, physicists, computer scientists and even, from time to time, the Dalai Lama.
So vexing has the problem of consciousness proved that some of these thinkers have been driven to a hypothesis that sounds desperate, if not downright crazy. Perhaps, they say, mind is not limited to the brains of some animals. Perhaps it is ubiquitous, present in every bit of matter, all the way up to galaxies, all the way down to electrons and neutrinos, not excluding medium-size things like a glass of water or a potted plant. Moreover, it did not suddenly arise when some physical particles on a certain planet chanced to come into the right configuration; rather, there has been consciousness in the cosmos from the very beginning of time.
The doctrine that the stuff of the world is fundamentally mind-stuff goes by the name of panpsychism. A few decades ago, the American philosopher Thomas Nagel showed that it is an inescapable consequence of some quite reasonable premises. First, our brains consist of material particles. Second, these particles, in certain arrangements, produce subjective thoughts and feelings. Third, physical properties alone cannot account for subjectivity. (How could the ineffable experience of tasting a strawberry ever arise from the equations of physics?) Now, Nagel reasoned, the properties of a complex system like the brain don’t just pop into existence from nowhere; they must derive from the properties of that system’s ultimate constituents. Those ultimate constituents must therefore have subjective features themselves — features that, in the right combinations, add up to our inner thoughts and feelings. But the electrons, protons and neutrons making up our brains are no different from those making up the rest of the world. So the entire universe must consist of little bits of consciousness.
Nagel himself stopped short of embracing panpsychism, but today it is enjoying something of a vogue. The Australian philosopher David Chalmers and the Oxford physicist Roger Penrose have spoken on its behalf. In the recent book “Consciousness and Its Place in Nature,” the British philosopher Galen Strawson defends panpsychism against numerous critics. How, the skeptics wonder, could bits of mind-dust, with their presumably simple mental states, combine to form the kinds of complicated experiences we humans have? After all, when you put a bunch of people in the same room, their individual minds do not form a single collective mind. (Or do they?) Then there is the inconvenient fact that you can’t scientifically test the claim that, say, the moon is having mental experiences. (But the same applies to people — how could you prove that your fellow office workers aren’t unconscious robots, like Commander Data on “Star Trek”?) Finally, there is the sheer loopiness of the idea that something like a photon could have proto-emotions, proto-beliefs and proto-desires. What could the content of a photon’s desire possibly be? “Perhaps it wishes it were a quark,” one anti-panpsychist cracked.
Panpsychism may be easier to parody than to refute. But even if it proves a cul-de-sac in the quest to understand consciousness, it might still help rouse us from a certain parochiality in our cosmic outlook. We are biological beings. We exist because of self-replicating chemicals. We detect and act on information from our environment so that the self-replication will continue. As a byproduct, we have developed brains that, we fondly believe, are the most intricate things in the universe. We look down our noses at brute matter.
Take that rock over there. It doesn’t seem to be doing much of anything, at least to our gross perception. But at the microlevel it consists of an unimaginable number of atoms connected by springy chemical bonds, all jiggling around at a rate that even our fastest supercomputer might envy. And they are not jiggling at random. The rock’s innards “see” the entire universe by means of the gravitational and electromagnetic signals it is continuously receiving. Such a system can be viewed as an all-purpose information processor, one whose inner dynamics mirror any sequence of mental states that our brains might run through. And where there is information, says panpsychism, there is consciousness. In David Chalmers’s slogan, “Experience is information from the inside; physics is information from the outside.”
But the rock doesn’t exert itself as a result of all this “thinking.” Why should it? Its existence, unlike ours, doesn’t depend on the struggle to survive and self-replicate. It is indifferent to the prospect of being pulverized. If you are poetically inclined, you might think of the rock as a purely contemplative being. And you might draw the moral that the universe is, and always has been, saturated with mind, even though we snobbish Darwinian-replicating latecomers are too blinkered to notice.
Jim Holt, a contributing writer, is working on a book about the puzzle of existence.