Epistolution: A Downward Causation Case Study
One of the more difficult ideas to grasp in the epistolution proposal is the idea of downward causation. What does this mean? What is an example of a system where the whole controls the behavior of the parts? This can be hard to imagine, because it relies on getting a sense of change that is not highly specific. Causal paths leading to changes in a system like this are not discrete and obvious but continuous, partial, and indirect. It seems to border on the absurd to say that “everything influences everything,” and this cannot resolve itself into a picture in one’s mind, so the whole idea can lose its force if you are not careful. So I thought of an example of a downward-caused system in which the domain itself is highly restricted, so the reader can get a sense of what I really mean here. Think of a thermometer. A thermometer is a downward-caused instrument that is restricted to only one narrow domain, temperature. In other words, in epistolution language, it has only a narrow niche that includes temperature and nothing much else. It is only sensitive to temperature.
What kind of a niche is temperature? Is the thermometer influenced by the temperature of the whole world? Well, yes, sort of. If you try to restrict the causation that changes the reading on the thermometer, you could imagine a ball of gas the size of a football around the thermometer, and say to yourself that only the speed of molecules inside this ball really impacts the thermometer reading. You could say that only this immediate envelope of space and the matter inside it are really having any impact on the level of the fluid in the thermometer, and that would be factually accurate. But if you inspect the boundary too closely, just like the human niche you will see an infinite regress, because of course the temperature of this football-shaped cloud of gas is affected by the gas around it that is the size of a beach ball, and the temperature of that ball of gas is affected by the temperature of the whole room, and the room affected by the weather, and so on. But still, the point remains that in order to read the temperature effectively for that football of gas, the thermometer does not need to be in touch with all the gas in the room, let alone all the gas in the whole world, it only needs to be located inside that football of gas for a period of time.
A thermometer takes the holistic condition of many millions of molecules, and translates it into a precise calculation of the temperature. This is a form of alphabetical templating. The thermometer reads out a temperature of 68 degrees Fahrenheit, and so this narrow aspect of the niche of the football of gas becomes a sort of translatable symbol, allowing comparison with other thermometer niches, and learning, and it serves a purpose for us. But we are only interested here in the way the whole controls a part. The whole condition of the niche has become a simple discrete reading. What is interesting here is not the fact that the reading happened at a particular time, but rather the way it happened. The speed of the molecules was condensed, in a sense, into a simplification. The thermometer too is made of molecules, and so in a sense it is just continuous with the ball of gas, and if we did not have any idea what it was we couldn’t distinguish anything significant about the level of the red fluid inside it. If we did not know it was a thermometer, it would appear to us just like the meaningless threads of condensation on the window of my apartment on a humid day…an insignificant pattern of matter written onto other matter by changing conditions. But since we have constructed the thermometer to be a template, the template holds information for us. The number 68 is a symbol which can be used in other scenarios. If we want to recreate part of the temperature-niche of the thermometer elsewhere, we have to construct a similar device and put it into a similar niche, and observe the results. No doubt the people who design thermometers do this quite a lot.
This metaphor reaches its limits when we try to imagine how a thermometer comes to be a thermometer. A thermometer is not a living thing, it has a human maker. The maker of the thermometer calculates that if he assembles a certain quantity of a certain fluid, glass of a certain shape and volume, and puts it into a frame with particular markings, then the whole apparatus will serve as a device for measuring temperature. So the thermometer is assembled not through downward logic but through upward logic. The parts the maker puts into place have independent characteristics, and are calculated to interact with each other to produce a temperature reading. This is upward causation. But now let’s suppose that instead of temperature readings recorded in numbers like 6 and 8, the thermometer was instead making tiny molecular structures, call them gemmules, based on the conditions it encountered during the day. Now suppose that these gemmules, when placed inside another football-shaped ball of gas at the right temperature, reacted to their environment in such a way as to link themselves together into a larger structure that became a second thermometer. That is what an organism is…it is a chain of gemmules recorded by downward causation that, when placed inside a suitable niche, can become another thermometer.
If you looked at the process only from the upward direction, the impetus would be mysterious. Why do the gemmules act the way they act? What gives them the logic that they follow? If you looked at the gemmules independently, they would look only like disconnected readings, the molecular equivalent of a bunch of 68s, 69s, 72s, and so forth, that were collected spontaneously from the environment of the thermometer during the day. They would have no intrinsic meaning. But as templates, these gemmules would allow for a new thermometer to grow by being open to being changed by the temperature within a suitable niche. Maybe this is still hard to envision. Let’s say there are several different gemmules numbered 67 that leap into place when the temperature strikes 67 in the niche. Likewise, when the temperature strikes 68 there are several more that do the same. Each of these gemmules, now in place, then facilitate the assemblage of more and more gemmules, until from a seemingly random toolbox of templates we eventually have a functional thermometer, as long as the temperature around them changed in an orderly way from one time to the next. The point here is that everything assembled by downward causation only has meaning when it is in context. In order for the pile of gemmules to make sense, we have to place them into a suitable niche, so that they can interact with one another in the right way. Without this, we are just reading the molecular equivalent of a bunch of random numbers.
The word “gemmule” is not my own invention; it is the name given by Charles Darwin to the then mysterious particles that were supposed to be the causes of the physical traits animals exhibit. He coined this term before Gregor Mendel’s work was known, assigning mechanism to genetic inheritance, and long before the structure and behavior of DNA was understood. I have intentionally left out of my thermometer metaphor any account of heredity. The reason I did this is because the heredity of the gemmules that turn into a thermometer…how the readings are written down and passed on, is actually not important to the argument I’m making. The point is that however these numbers arrive into a suitable niche, downward causation explains how they are assembled into a functional structure. In the paragraph above, i have also skipped explaining what logic the downward causation exerts on the gemmules to make them simply “leap” into place. Why do they leap instead of stumble, or roll? Why do they leap at the right time and not the wrong time? It is this mechanism that the epistolution formula in my paper is designed to explain.
If we look at this system from the upward perspective, it could seem like the gemmules were the ones assembling themselves, not as readings of the temperatures, but as individual agents. It could seem like the gemmules had purposive behavior, leaping this way and that. But from this example I hope you can see that the purposive behavior is not intrinsic to the gemmules, it is only lent to them by their position in the context of the niche, and only as a result of the downward actions of many previous niches onto the library of templates, trimming out the useless ones and filling their places with useful ones. It is the context that really has purpose. If any given gemmule was not created, its place would be filled by another one, because the readings are directed by the set of conditions inside the niche. To use another example, if you lose one of the readings on a long chart of astronomical observations, you have a gap in your data, but it does not invalidate the whole set of numbers. These numbers, like the gemmules, are caused by the galactic system above the numbers, they are not independent causal agents. If you make similar observations of the same galaxy the next night, you can easily build a replacement for your lost observation. Genes are the same sort of thing.
