Tuesday, July 30, 2013
The Socratic philosophers regarded sight as the most perfect of the senses (see Hans Jonas’ superb collection of essays, The Phenomenon of Life). This judgment rested on two observations. One is that sight, more than any of the other senses, gives us the best, immediate grasp of what each thing is. The other is that sight allows us to observe something without necessarily interacting with it.
I have spent most of the last month in the company of mountains, in the Bighorns in north central Wyoming, Yellowstone National Park, and finally a short side trip to Devil’s Tower. Viewing mountains as I approached and circled them gave me more reasons to agree with the ancients.
I backpacked in and camped not far from Lost Twin Lakes in the Bighorns. This is a magnificent cirque rising about two thousand feet above the alpine lakes. The upper lake is about 10,300 feet. Our camp was about a thousand feet lower than that.
In the photo above, you are looking across the lower lake at the central and most impressive face in the cirque. This was my third visit to this hallowed ground, but for some reason it was the first time I noticed how deceptive the view is. It appears as if the scree field beginning at the bottom of the central face goes all the way down to the edge of the lake in view. In fact, there is another lake between the camera and the rock wall. It is hidden from view by the rise at the distant shore.
This is the problem of the middle ground, something that you cover if ever you study Renaissance art history. It is fairly easy to draw or paint the foreground and the background. Fitting in the middle ground is so difficult that many medieval painters went to great lengths to hide it or simply ignored it altogether.
It strikes me that this has deep philosophical implications. When someone tries to see the world as it is, it tends to present itself either as what immediately surrounds the observer or as the larger horizon in which the immediate surroundings are set. This leaves a gap between the particular, up close reality and the big picture. It is very difficult, perhaps impossible, to understand how the human scale fits into the whole of things.
Moreover, the big picture is always hiding more than it reveals. No matter how clear the larger image (or concept) of the whole is, it is always incomplete. The philosopher Leo Strauss thought that this might be an insurmountable obstacle to wisdom. Philosophy is the attempt to replace opinions about the whole (which is to say, perspectives on it) with knowledge of the whole. To do that, one would have to have not only an accurate view of the big picture but an equally accurate view of all the parts and how they fit together. This is probably not something that we can achieve; hence, philosophy will always be the pursuit and never the accomplishment of wisdom.
It strikes me that this existential fact presents itself in all the questions I am interested in. How can we understand living organisms both as they present themselves to common sense observation and as they fit into the world of inorganic physics? It may be that viewing organisms either way necessarily obscures something essential in the other.
Trying to do what can never be done is a special case of what is uniquely human. The more general case is doing something that can be done but is hard when we have no obvious reason to do it. My son and I walked sixteen miles in two days for the privilege of eating freeze dried food and sleeping in a thin skinned tent in bear country. Yes, Heart Lake was very beautiful and we spent our evening walking around deep thermal pools (about 190 degrees) not far from camp. We were rewarded when a small geyser announced its presence by spewing steam and water thirty feet into the air. Of course, we enjoyed the same kind of sights down lower with board walks for comfort and only a few yards to walk.
Lest I think myself the least bit heroic, today I watched through binoculars as a woman climbed up a furrow high on the side of Devil’s Tower. Why do we do such things? There was this fellow whose name I forget who built a special rowboat and using nothing but muscle crossed the Pacific Ocean from Japan to Oregon. When asked why he did it, he replied that only animals do useful things.
Saturday, July 20, 2013
In Chapter 5 of What is Life? Addy Pross considers theories of the origin of life on earth. There is a lot in here to chew on, but I will focus on a couple of themes. One is the relationship between historical and ahistorical explanations.
Historical explanations of abiotic genesis concern the question of how life actually did emerge from inorganic matter. Ahistorical explanations concern how organically complex systems could have emerged, given some propitious set of circumstances. If we knew how life did emerge, it would obviously help us understand the physical processes that made such an event possible. Likewise, if we understood how life could have emerged it would help us determine what to look for in the geological record. Unfortunately, we don’t have plausible answers to either question. This reminds me of an old joke. There are two ways for a man to deal with a woman. Nobody knows either one of them.
The second theme is the dichotomy involving metabolism first accounts of the origin of life and replicator first accounts. Metabolism is the regulation of chemical reactions that makes all organic processes possible. Materials have to be exchanged with the environment and transformed within cells. Energy must be acquired and expended for this to happen.
Metabolism first explanations of life’s origin hold that it begins with a holistic, autocatalytic reaction among inorganic chemicals. Suppose that molecule A catalyzes molecule B; B catalyzes C; C, D; and D in turn catalyzes A. You know have a potentially self-sustaining cycle. Perhaps that’s how life got started: digestion precedes reproduction.
Replicator first accounts look to molecules that can replicate themselves. Chain A-B-C can catch an additional A, which catches a B, which catches a C. At that point the C-A connection breaks, and we have two A-B-C molecules.
In existing organisms, metabolism and replication support one another. It is very unclear how either could get going by itself, let alone both of them independently. If Pross’ survey is fair, no one knows how either could climb “uphill” against the second law in order to produce even the simplest organisms.
I keep waiting for some sign of how a reductionist account of life might be possible, as Pross promised. I haven’t got to the end yet, but I am getting rather near it. Meanwhile, I am sticking with Aristotle. Life looks to me as if it were ontologically irreducible to the same laws that seem to govern inorganic matter. I am not arguing for some deus ex machina. I think, rather, that the appearance of life tells us something about inorganic matter that we could not possibly guess were life not in evidence.
I have been walking up high of late, in the Bighorn Mountains of Wyoming. I haven’t had much time for reading or for this blog, but I did pick up Addy Pross’ What is Life again tonight.
Pross argues that there is a law governing “dynamic kinetic systems” (i.e., living organisms) that is analogous to the second law of thermodynamics. Systems governed by the second law tend toward more chemically, physically, and especially thermal stable states. Here is the second law:
The entropy of an isolated system never decreases.
That is to say, an isolated system (one in which no additional energy is supplied) tends toward thermal equilibrium. An ice cube floating in a glass of scotch represents a highly order system (low entropy): the cold and the warm stuff are neatly separated. As the ice melts, the system becomes steadily less ordered until it reaches equilibrium (high entropy).
Systems governed by Pross’ analogous law tend toward more stable replication. Here is Pross’ new law:
Replicating chemical systems will tend to be transformed from (dynamically) kinetically less stable to (dynamically) kinetically more stable.
This law would underwrite the course of evolution. Ants, for example, are very kinetically stable so they remain in their form for a very long period in evolutionary history. Okay.
All material transformations, including all that go on in living organisms, are governed by the second law. Only replicators are governed by the Pross law. Replicators include all organisms but also replicating molecules like RNA.
Here is an analogy that I think captures this point. Consider an alley that slopes slightly downhill. It ends in an intersection with a second alley that slopes from right to left. A boulder rolling down the first alley will always go left when it reaches the junction, because boulders always roll downhill.
A man walking down the first alley is just as much subject to the laws of gravity as the boulder. Nonetheless, the man may turn right at the junction and walk uphill. In order to accomplish this task, the solitary walker must expend stored reserves of energy. If he wants to keep resisting gravity, he will eventually have to replenish his store of energy‑perhaps at the pub atop the hill.
The existence of uphill walkers, while scrupulously observant of the second law of thermodynamics, seems to depend also on Pross’ second law. Organisms exist in forms that are more dynamically stable in the environmental niches that they occupy than the forms from which they evolved.
All that seems reasonable; however, it still seems to me that dynamic stability is a very different kettle of fish from thermodynamic stability. The latter needs only material and efficient causation, as Aristotle described them. The latter, this rock bumped that rock and made it move, is underwritten in modern physics by the second law. Pross’ law of dynamic kinetic stability requires Aristotle’s other two causes: formal (it is this kind of organism) and final (it is up to something).
The big problem for modern biology is how to reconcile the two pairs of Aristotelian causation. Pross’ highly critical discussion of theories about the origin of life illustrates this very well.
Friday, July 5, 2013
My daughter has been very good at a lot of things and one of those things was civilizing hamsters. Her first and best subject was Snuffles, a pocket-sized rodent the color of a calico cat. Whenever she reached her hand into his realm he would instantly climb on board. Her favorite trick was to come downstairs in her long nightshirt when a guest was in the living room. She would stand there smiling and, after a dramatic pause, Snuffles would hoist his head out of her shirt pocket and present himself to the assembly.
One day he hoisted himself too far, and fell headlong to the hardwood floor. Snuffles began shrieking wildly in what I took to be the hamster version of profanity and then he stood up on his hind legs and reached his forepaws towards his savior.
I am well aware of the anthropomorphizing in my account, so I won’t push it. I will say that this behavior seems so obviously to indicate pain, fear, and a desire for comfort, that the burden of proof is heavily on the side of anyone who would argue that the animal lacked conscious awareness.
Snuffles might be pleased to know that his consciousness has now been endorsed by an authoritative body. Bonnie Chojnacki alerts us to the event at the IPSA Research Committee 12 Facebook page. Here is the story from io9:
An international group of prominent scientists has signed The Cambridge Declaration on Consciousness in which they are proclaiming their support for the idea that animals are conscious and aware to the degree that humans are — a list of animals that includes all mammals, birds, and even the octopus. But will this make us stop treating these animals in totally inhumane ways?
I have to say that I find the science in the Declaration to be underwhelming and occasionally philosophically confused. Consider this bit:
Birds appear to offer, in their behavior, neurophysiology, and neuroanatomy a striking case of parallel evolution of consciousness. Evidence of near human-like levels of consciousness has been most dramatically observed in African grey parrots. Mammalian and avian emotional networks and cognitive microcircuitries appear to be far more homologous than previously thought. Moreover, certain species of birds have been found to exhibit neural sleep patterns similar to those of mammals, including REM sleep and, as was demonstrated in zebra finches, neurophysiological patterns, previously thought to require a mammalian neocortex.
All of that is wonderful, but how, exactly, does it amount to an “observation” of “evidence of near human-like levels of consciousness”? Consciousness is, famously, private in the most fundamental way. It is directly observable only in the first person. I infer it in you and vice versa by way of analogy. I figure that you scream when you hit your head for the same reason that I do. The same reasoning is extended to animals by anyone who has seen a hamster fall out of a pocket.
The neurophysiological arguments in the Declaration may be understood as one more analogy. I have this set of cognitive microcircuitries and I am conscious; my friend’s parakeet Hertzl had the former, therefore he had the latter. Okay, but it’s still just another analogy. It might add a lot if not for the fact that a very large portion of my microcircuitries underwrite phenomena that occur below the level of consciousness.
We are still largely dependent here on common sense, which is in many cases the only guide we have. Until we have some idea of how the physics gives rise to the phenomenon of consciousness, we haven’t got much further than that.
I think we need an evolutionary account of consciousness. Our awareness is one of the most mysterious and wonderful things that we have ever observed in nature. It would be very odd indeed if it were not selected for. Something about consciousness provides organisms with a hitherto unavailable flexibility in their behavior. Pursuing the problem in that light, we might be able to better guess which organisms are good candidates for sentient beings. Then the neurophysiological substrates of consciousness could be identified as targets of selection.
All that said, I am also rather skeptical of such a declaration in the first place. The declaration is political in intent. I doubt very much whether it will have any effect on how we treat animals, but it is surely supposed to have such an effect. It is not clear to me that the scientific status of the signatories or the fact that it was “The declaration was signed in the presence of Stephen Hawking,” has any more political significance than the fact that “the signing ceremony was memorialized by CBS 60 Minutes”. Scientific authority is not political authority.
Likewise, the fact that a lot of scientists signed the Declaration has no scientific significance. Science is not decided by vote and consensus has no scientific weight. So while I share the scientific opinion of the signatories that very many animals are conscious and I share their political opinion that we ought to care about how we treat animals, I think that such a declaration confuses these issues.