The Emergence of Constraint

 Sequences at the Dinner Table

How does symbolic information actually get control of physical systems? Let’s start by looking at an everyday interaction between sequences and a humanshaped physical system. Imagine you are dining with friends and you would like someone (let’s call him Peter) to pass the pepper grinder to you. How do you arrange for Peter to do this? I can think of three possible ways.

Most likely you would simply say: “Please pass the pepper, Peter,” relying on a sequence of pulses in the air to induce Peter to modify his body’s trajectory to comply with your request. “Language is an efficient way to change another’s behavior,” writes psychologist Charles Catania. “By talking, we can change what someone else does.”1 This is one way that sequences get control of physical systems.

You could also wave your hand at him to get his attention and then point to the pepper. In this case, you hope that he will attend to your hand-waving and understand from the context that you want him to pass the pepper. Anthropologist Thom Scott-Phillips calls this ostensive-inferential communication: ostensive because you are trying to demonstrate what you want Peter to do, and inferential because you are relying on Peter to figure out from the context how to behave.2 We share such gestural systems with our non-human primate relatives.

But there is also a purely mechanical solution that is possible in principle, even if fanciful in practice. You could design and construct a prosthetic harness of cuffs, belts, pulleys, and motors that would attach to Peter’s body and coordinate the trajectories of his arms and hands so that he would pass the pepper to you. In effect this would convert Peter into a puppet. He would not control his movements; the harness would.

My point is that all three solutions—harness, gesture, and request—are functionally equivalent; each guides the motion of Peter’s arm, hand, and fingers to deliver the pepper to you. In all three scenarios Peter’s body is constrained to move in a specific, highly coordinated way. Strangely, though, the harness is the simplest of the three to explain in purely physical terms. It is a machine that requires energy to function and which operates in accordance with the laws of nature. This may be an absurd way to get the pepper to you, but its engineering principles are readily understood.

More difficult to explain is how a sequence of pulses in the air leads Peter to behave as though his trajectory were being controlled by a machine. The pulses in the air are not machines and we know they entail little energy, yet their real-world effects are equivalent to an energy-consuming machine, and a complicated one at that.3 “Language,” writes Mark Pagel, “equips you with something akin to a television remote control device, capable of sending invisible digital signals that reprogram your listener.”4 Thinking about pepper-passing this way entails a novel perspective on the function of speech. As noted in Chapter 1, it has physical effects without causing them directly.

Peter is complicated, as is the culture in which he is embedded, but living systems like Peter and rituals of civilization like suppers nonetheless obey the laws of nature. When we perceive Peter moving his arm toward the pepper, we do not assume supernatural forces are at work. If we think about it at all, we assume the coordinated muscle contractions and nerve impulses that cause his arm to move are due to natural forces. However, as Richard Dawkins says, “If we are going to explain the universe in terms of blind physical forces, those blind physical forces are going to have to be deployed in a very peculiar way.”5

Of course, it is always possible that Peter would spontaneously pass the pepper to you without being asked, but that is unlikely. It is also possible that Peter might not hear you, might ignore your request, might resist the harness, etc. so that you do not get the pepper. Your speech cannot force him to move; it is inert. Each of our three methods starts with an action that is possible but improbable—he might pass the pepper without being asked—and converts it into an action that is probable though not certain. In the words of philosopher Gottfried Leibniz, such requests incline without necessitating; they make Peter’s action more likely but do not have the wherewithal to make it mandatory.6

So, how likely is it that you will get the pepper? If you stay silent, it is unlikely, though not impossible. If you speak up, getting the pepper becomes likely, though not certain. Here, in two quick sentences, we have somehow transcended the world of physical law. Under the inexorable laws of nature, actions are either certain or they are impossible. Physical law has no way to account for patterns of behavior that are somewhere in between, like life and civilization.