One of the crucial notions of the Ant Fugue is the “caste distribution” or “state,” for it is claimed that that is a causal agent in determining the future of the organism. Yet this seems to contradict the idea that all of a system’s behavior comes from underlying laws—those of ants of neurons, in the case of colonies or brains—but ultimately, in either case those of particles. Is there such a thing as “downward causality” put starkly, the notion that “a thought can influence the path of an electron”?
In Inside the Brain by William Calvin and George Ojemann, there is a provocative series of questions asked about a neural firing. “What starts it?” they ask. What causes the sodium channels to open up? (The function of the sodium channels is to let sodium ions into the neuron, and when their concentration is high enough, that then triggers the release of the neurotransmitters, whose flow from one neuron to another constitutes the essence of neural firing.) The answer is, the sodium channels are voltage-sensitive, and they have just been hit by a strong enough voltage pulse to flip their state from closed to open.
“But what causes the voltage to rise originally, so that it crosses this threshold … and sets off this sequence of events called the impulse?” they go on. The answer is, various “nodes” along the neuron’s axon have simply relayed this high voltage from one station to the next. So then the question is again transformed. This time they ask, “But what causes the very first impulse to occur at the very first node? Where does that voltage shift come from? What precedes the impulse?”
Well, for most neurons inside the brain—“interneurons,” meaning neurons that are fed into not by sensory input but only by other neurons—the answer is, their first node’s voltage shift is provoked by the total effect of the pulses of neurotransmitters coming in from other neurons. (We could call those neurons “upstream” neurons, but that would imply, quite falsely, that the flow of neural activity in the brain follows a line in only one direction, in the manner of a river. In fact, as a rule, neural flow patterns are far from linear and make loops all over the place, quite unlike rivers.)
Thus we seem to get into a vicious circle—a chicken-and-egg type of riddle. Question: “What triggers a neural firing?” Answer: “Other neural firings!” But the real question remains unanswered: “Why those neurons, and not others? Why this vicious circle and not another neural loop in another part of the brain?” To answer this, we have to shift levels and talk about the relationship of the brain to the ideas it encodes, which then would require us to talk about how the brain encodes, or represents, its concepts about the world. Since we do not wish to theorize in this book on the details of such matters, we will talk about a related but simpler concept.
Imagine an intricately bifurcating and rejoining domino-chain network. Suppose that each domino has a little time-delayed spring underneath it that stands it up again five seconds after it has fallen. By setting up the network in various configurations, one could actually program the system of dominoes to perform calculations with numbers, exactly as one could a full-scale computer. Various pathways would carry out various parts of the calculation, and elaborate branching loops could be set up. (Note how this image is not too different, then, from that of networks of neurons in a brain.)
One could imagine a “program” trying to break the integer 641 into the product of its prime factors. “Why isn’t this particular domino ever falling down?” you might ask, pointing at one that you’ve been watching for a long time. An answer on one level would be “Because its predecessor never falls.” But that low-level “explanation” only begs the question, What one really wants—the only satisfying answer, in fact—is an answer on the level of the concepts of the program: “It never falls because it is in a stretch of dominoes that gets activated only when a divisor is found. But 641 has no divisors—it is prime. So the reason that domino never falls has nothing to do with physics or domino chains—it is simply the fact that 641 is prime.”
But have we then admitted that higher-level laws actually are responsible, and govern the system above and beyond lower-level laws? No. It is simply that an explanation that makes any sense demands higher-level concepts. The dominos certainly don’t know they are part of a program nor do they need to—any more than the keys of a piano know, or need to know, which piece you are playing. Think how strange it would be if they did! Nor do your neurons know that they are involved in thinking these thoughts right now, nor ants that they are part of the grand scheme of their colony.
There is a further-back question that might arise in your mind “What laws, at what level, are responsible for the existence of the program and the domino chains—indeed, for the manufacturing of the dominoes at all?” To answer this and the many questions it inevitably triggers we are sent sailing backward in time over larger and larger spans, back into all the reasons our society exists, back to the origin of life, and so on. It is more convenient to sweep these many questions under the rug and simply to leave our reason as: the primeness of 641. We prefer this kind of compact higher-level explanation, one that eliminates long view into the past and that concentrates on the present or the timeless. But if we want to trace events to their ultimate causes, we are forced into reductionistic views as described by Dawkins or the Tortoise. Indeed ultimately we are sent back to the physicists, who will refer us to the “Bi Bang” as the primordial cause of everything. This is not satisfying, how ever, because we want an answer at a level that appeals to concept familiar to people—and, fortunately, nature is stratified enough that this is often possible.
We asked whether a thought can influence the course of an electron in flight. The reader could easily conjure up an image we do not have in mind—namely, of a deeply concentrating “psychic” with furrowed brow beaming his “waves of Plutonian energy” (or whatever he calls them) outwards toward an object—say a tumbling die—and influencing the way it will land. We do not believe in anything of the sort. We do not believe that there is some as yet undiscovered “mental magnetism” through which concepts could “reach down” and, through some sort of “semantic potential,” alter the paths of particles, making them deviate from what present-day physics would predict. We are talking about something else. It is more a question of where explanatory power comes from—perhaps a question of the proper ways of using words, a question of how to reconcile everyday usage of terms like “cause” with the scientific usage of those terms. Thus, is it reasonable to explain the trajectories of particles by making references to higher-level notions such as “beliefs,” “desires,” and so forth? The reader may detect that we see much utility in adopting this way of speaking. Just as evolutionary biologists feel free to use “teleological shorthand” to condense their concepts down to an intuitively reasonable size, so we feel that people who study the mechanisms of thought must necessarily become conversant with ways of translating back and forth between purely reductionistic language and a sort of “holistic” language in which wholes do indeed exert a visible effect on their parts, do indeed possess “downward causality.”