Minds exist in brains and may come to exist in programmed machines. If and when such machines come about, their causal powers will derive not from the substances they are made of, but from their design and the programs that run in them. And the way we will know they have those causal powers is by talking to them and listening carefully to what they have to say.
D.R.H.
Once upon a time there was a dualist. He believed that mind and matter are separate substances. Just how they interacted he did not pretend to know—this was one of the “mysteries” of life. But he was sure they were quite separate substances.
This dualist, unfortunately, led an unbearably painful life—not because of his philosophical beliefs, but for quite different reasons. And he had excellent empirical evidence that no respite was in sight for the rest of his life. He longed for nothing more than to die. But he was deterred from suicide by such reasons as: (1) he did not want to hurt other people by his death; (2) he was afraid suicide might be morally wrong; (3) he was afraid there might be an afterlife, and he did not want to risk the possibility of eternal punishment. So our poor dualist was quite desperate.
Then came the discovery of the miracle drug! Its effect on the taker was to annihilate the soul or mind entirely but to leave the body functioning exactly as before. Absolutely no observable change came over the taker; the body continued to act just as if it still had a soul. Not the closest friend or observer could possibly know that the taker had taken the drug, unless the taker informed him.
Do you believe that such a drug is impossible in principle? Assuming you believe it possible, would you take it? Would you regard it as immoral? Is it tantamount to suicide? Is there anything in Scriptures forbidding the use of such a drug? Surely, the body of the taker can still fulfill all its responsibilities on earth. Another question: Suppose your spouse took such a drug, and you knew it. You would know that she (or he) no longer had a soul but acted just as if she did have one. Would you love your mate any less?
To return to the story, our dualist was, of course, delighted! Now he could annihilate himself (his soul, that is) in a way not subject to any of the foregoing objections. And so, for the first time in years, he went to bed with a light heart, saying: “Tomorrow morning I will go down to the drugstore and get the drug. My days of suffering are over at last!” With these thoughts, he fell peacefully asleep.
Now at this point a curious thing happened. A friend of the dualist who knew about this drug, and who knew of the sufferings of the dualist, decided to put him out of his misery. So in the middle of the night, while the dualist was fast asleep, the friend quietly stole into the house and injected the drug into his veins. The next morning the body of the dualist awoke—without any soul indeed—and the first thing it did was to go to the drugstore to get the drug. He took it home and, before taking it, said, “Now I shall be released.” So he took it and then waited the time interval in which it was supposed to work. At the end of the interval he angrily exclaimed: “Damn it, this stuff hasn’t helped at all! I still obviously have a soul and am suffering as much as ever!”
Doesn’t all this suggest that perhaps there might be something just a little wrong with dualism?
Reflections
“O Seigneur, s’il y a un Seigneur, sauvez mon âme, si j’ai um âme.”
“O Lord, if there is a Lord, save my soul, if I have a soul.”
—Ernest Renan
Smullyan provides a provocative riposte to Searle’s thrust—an intentionality-killing potion. The soul of a sufferer is annihilated and yet, to all , external eyes, the suffering goes on unabated. What about to the inner “I”? Smullyan leaves no doubt as to how he feels.
The point of this little fable is the logical absurdity of such a potion. But why is this? Why can’t the soul depart and leave behind a soulless, feelingless, yet living and normal-seeming being?
Soul represents the perceptually unbreachable gulf between principles and particles. The levels in between are so many and so murky that we not only see in each person a soul but are unable to unsee it. “Soul” is the name we give to that opaque yet characteristic style of each individual. Put another way, your soul is the “incompressible core” that determines how you are, hence who you are. But is this incompressible core a set of moral principles or personality traits, or is it something that we can speak of in physical terms—in brain language?
The brain’s neurons respond only to “local” stimuli—local in both space and time. At each instant (as in the Game of Life, described in the Reflections on “Non Serviam”), the neighboring neurons’ influences are added together and the neuron in question either fires or doesn’t. Yet somehow all of this “local” behavior can add up to a Grand Style—to a set of “global” principles that, seen on the level of human behavior, embody long-term goals, ideals, interests, tastes, hopes, fears, morals, and so on. So somehow all of these long-term global qualities have to be coded into the neurons in such a way that, from the neurons’ firings, the proper global behavior will emerge. We can call this a “flattening” or “compressing” of the global into the local. Such coding of many longterm, high-level goals into the synaptic structures of billions of neurons has been partially done for us by our millions of ancestors, way back in the evolutionary tree. We owe much not only to those who survived, but also to those who perished, since it is only thanks to the multiple branchings at every stage that evolution could work its miracles to give rise to a creature of such complexity as a person.
Consider a simpler animal, such as a newborn calf. An hour-old calf not only can see and walk, but will instinctively shy away from people. Such behavior comes from ancient sources—namely, the higher survival rate of “protocows” that had genes for this kind of behavior. Such behavior, along with a million other successful adaptations, has been “flattened” into neural patterns coded for in the bovine genes, and is now a ready-made feature of each calf as it comes off the assembly line. Seen on its own, the set of cow genes or human genes seems a miracle—nearly inexplicable. So much history has been flattened into molecular patterns. In order to demystify this, you would have to work backward, reconstructing the evolutionary tree—and not just the branches that survived! But we don’t see the whole tree of predecessors, successful and otherwise, when we look at an individual cow, and so we can be amazed by the long-term purposes, goals, and so forth that we see flattened in its brain structure. Our amazement is particularly great when we try to image how, inside its head, millions of individually purposeless local neural firings are adding up to a coherent purposive style-the soul of one cow.
In humans, by contrast, the mind and character continue to shaped for years after birth, and over this long time span neurons absorb feedback from the environment and self-modify in such a way as to build up a set of styles. The lessons of childhood are flattened into unconscious firing patterns, and when all of these tiny learned neural patterns act in concert with the myriad tiny neural patterns coded for in genes, a human perceiver will see one large pattern emerge—the soul of one human. This is why the idea of a potion that “kills the soul” and yet leaves the behavior patterns invariant makes no sense.
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“An Unfortunate Dualist” from