Labyrinths of Reason (13 page)

The test would have to be a way of “getting inside someone else’s head” and feeling what the other person feels (or doesn’t feel). ESP, if it exists, might allow that; so might some sort of futuristic brain experiment in which one person’s brain is artificially linked to another’s. Even these exotic measures might not eliminate doubt entirely.
It still could be that you are the only person with consciousness and are responding to “brain waves,” “auras,” or “vibrations” produced by the automatonlike brains of others.

Most philosophers concede that whether others experience consciousness is strictly unknowable. Some take this one step further and argue that consciousness and perfect simulation of consciousness are the same. Here most people object. You probably feel that there
is
a difference between consciousness and the lack thereof, even while admitting that no possible observation or experiment would establish it. Is this a rational objection?

A clever recent twist on Poincaré’s thought experiment asks what would happen if everyone’s sensations of pleasure and pain doubled overnight. It is considerably less clear than in the original that this is meaningless, though some of the same reasoning applies.

In 1911 economic theorist Stanley Jevons wrote:

Jevons is saying that, just possibly, your friends’ sensations are a thousand times greater than your own. Or a thousand times less. Consider, then, this thought experiment:

During the night, pleasure/pain doubles—meaning that any particular stimulus, such as a slice of pecan pie, sexual climax, or a bee sting, henceforth causes twice the pleasure or pain that it did before. It must be stipulated that only the
subjective
sensations are doubled. Pleasure and pain are associated with certain measurable brain activities. Were the levels of endorphins (brain chemicals associated with some types of pleasure) higher, or were there a measurably increased electrical activity of the C fibers (which have been associated with pain), the change would obviously be detectable to a neurologist. Not so obvious is whether a subjective doubling would be detectable.

The first thing to ask is if preferences (the choices you would make when free to make them) would be any different. Presumably
not, since preferences seem to be based only on relative degrees of pleasure and pain.

Philosopher Roy A. Sorensen concluded that a doubling of preferences would not be detectable. You walk into an ice-cream shop the day after the change. The shop has thirty flavors of ice cream, of which twenty-nine you like in varying degrees, and one (licorice) you detest. Since pleasure/pain has doubled, the licorice ice cream is twice as loathsome now. Of course, you wouldn’t have ordered licorice even before the doubling. You would have ordered your favorite flavor, unless the desire for novelty was strong enough to override that preference and lead you to choose another.

Now, after the doubling, you do the same thing. The favorite flavor beats out the second favorite by twice as big a margin. The pleasure of novelty is twice as great too, and you might elect to try a new flavor rather than your favorite, but only if you would have done so even had the doubling not occurred. In general, diners would make the same selections from menus; so would condemned criminals given their choice of execution method; it would neither help nor hurt any television show’s market share.

George Schlesinger (who argued that Poincaré’s physical doubling would be detectable) claimed that a doubling of preferences would be detectable through indiscernible preferences. He argued, in effect, like this: Suppose that if given a choice between a bee sting and a wasp sting you cannot decide because each gives you almost precisely the same degree of pain. After pleasure/pain is doubled, however, there is more “room” between them on your personal scale of preferences, and you can see that the bee sting actually hurts less. You might even be able to find some pain that fits between them. Maybe it would be evident that you prefer a tax audit to a bee sting, and a wasp sting to a tax audit. Sorensen countered that this is no different from saying that a nocturnal doubling of length could be detected by reexamining pencils that had previously seemed to be exactly the same length!

The pleasure principle of Freudian psychology claims that we always choose to do what is most pleasurable (whether for the moment or in the foreseeable long run). If that is true, it should not matter that the most pleasurable thing is twice as pleasurable. On the television quiz show
Jeopardy
, contestants answer questions on a game board for designated amounts of money. After a commercial break, they start with a new board called “Double Jeopardy,” where each question is worth twice as much. Obviously, the strategy for “Double Jeopardy” is exactly the same, even though you
win twice as much money. This agrees with a basic tenet of decision theory, which says that multiplying “utility” (a numerical measure of how much one desires or does not desire a particular outcome) by two or any positive factor makes no difference. What was preferred before will still be preferred.

Some have pointed to the “pleasure center” experiments of James Olds and Peter Milner as proof that a doubling of pleasure/pain would be noticeable. In the early 1950s, Olds and Milner implanted electrodes of silver wire in the brains of rats to see how electrical stimulation of the brain could influence behavior. They were looking for hypothetical “avoidance centers” where stimulation would teach rats to avoid behaviors. The rats roamed freely across a table. When a rat approached one corner, the experimenters applied an electrical impulse (5 to 100 microamperes for half a second) to the embedded electrode.

Olds and Milner found very strong avoidance centers. Stimulating these parts of the brain as a rat approached the forbidden corner caused it to turn around and flee. A single such experience taught the rat to steer clear of the corner indefinitely. Then came one of the accidents that are so much a part of the history of science. As one rat approached the corner and received its electrical stimulation, it stopped. It moved a few steps further toward the corner, and stood fast. When moved away from the corner, it tried to return. Olds and Milner examined the rat more carefully and found that its electrode had been implanted in a slightly different part of the brain. This part of the brain had the opposite function from the avoidance centers.

This new site came to be called a “reward” or “pleasure” center. Conversely, the avoidance regions were guessed to be sites of pain. Rats would readily learn their way through mazes to receive stimulation of the pleasure centers. Rats that were allowed to stimulate their pleasure centers by pressing a lever soon did nothing else. They pressed the levers a hundred times a minute until they collapsed of exhaustion; after brief sleep, they immediately began again.

The identification of the sites as pleasure and pain centers was tentative. Olds and Milner faced a rodent “other minds” problem: Do rats experience pleasure and pain as we do, or are they virtual automatons? Later experiments were done on human volunteers. The sensation produced by stimulating a pleasure center was pleasurable (but not nearly so compelling as it seems to be with the rats). Psychologists have identified dozens of distinct pleasure centers
of the brain, associated with sex, food, thirst, and other basic desires.

The feeling of some is that if pleasure/pain doubled, we would all be like Olds and Milner’s rats, immersed in a nonstop orgy of pleasure. In Olds and Milner’s experiments, however, the pleasure of just one action (that of pressing the lever in the cage) increased unilaterally. That made the rat’s preferences different. If every action increased in pleasurableness equally, the situation would be much more similar to Poincaré’s original situation.

Suppose you are in the ice-cream shop eating a dish of your favorite flavor of ice cream. It tastes twice as good as it ever did. Does that mean you would gorge yourself on it? The stomachache you would get from eating too much ice cream is now twice as unpleasant; you are watching your fat intake and hate to go off your diet twice as much. Also, you are constantly making a choice between eating and doing something else. Eating has high priority when you are hungry; when sated, it has low priority. All the other things you could be doing instead of having a second dish of ice cream would be twice as attractive too.

Even if people acted the same, wouldn’t they still be aware of the doubling? You might detect the change by comparing your current pleasure and pain with memories of past experiences. The fact that we make statements like “This is the best pecan pie I ever tasted” shows that we carry memories of past pleasures and can use them to gauge current ones.

I tend to agree with this and yet am unsure just how it is different from a statement like “From the looks of it, the Sears Tower is the tallest building I’ve ever seen.” The height of a building is judged in one of two ways. The objective way is to consult published accounts of its height. A guidebook lists the height of the Sears Tower as 1454 feet; you can compare this with the heights of other tall buildings you have seen and conclude that the Sears Tower is the tallest. How would you compare pleasure/pain objectively? It could only be through published accounts of past preferences (such as results of a wine tasting comparing vintages). Those accounts would compare (old) degrees of pleasure/pain to other (old) pleasures and pains and would therefore be of no help at all. It would be like trying to gauge the height of a doubled Sears Tower with doubled yardsticks.

The subjective way of gauging a building’s height is by comparing it with nearby buildings, the angle you must turn your head to see its top (in effect, a comparison with your own height), etc. It is likely that some of our experience of pleasure and pain entails a
comparison with contemporaneous pleasure and pain. (The best meal you ever tasted was what you had after spending all that time at summer camp/in prison/on a raft with no food; hitting your head against the wall feels good when you stop; euphoria follows the pain of giving birth.) With all pleasures and pains doubled, such comparisons would fail to detect the change.

If you feel that memories would give away the change, let the change occur gradually (even over a period of centuries). Is there anything Plato could have written that would convince us that the Hellenes felt twice the pleasure and pain that we do in the effete twentieth century?

More difficult to refute is the claim of some philosophers that stress would be greater. What if you walk into a foreign gambling casino, find a green roulette chip on the floor, and use it to place a bet on lucky number 7? It’s a 100-smackeroo chip, which you figure to be worth $2 American. Just after you irretrievably place the bet, a friend tells you that you made a mistake about the exchange rate, that the chip is actually worth $2000. You will either lose the $2000 or win $72,000. The ratios of the wins and losses are exactly the same, but still, wouldn’t you be more jittery with the higher stakes? It appears there would be greater stress in a world with doubled pleasure/pain. There would always be twice as much to gain and twice as much to lose.

One response is that, yes, there would be twice as much stress, because stress is a form of pain and is doubled. The ratios would still work out the same. On the other hand, this stress might be manifested in a higher rate of ulcers, increased use of tranquilizers, greater suicide rate, etc.—objective changes.

Arguably, sadists and masochists would detect a doubling of pleasure/pain. Not only would sadists derive twice as much pleasure from inflicting a given amount of pain, but any given cruelty would cause twice as much pain. A sadistic act would cause twice the pain, and thus four times the pleasure. Comparable reasoning applies to masochists: Their pain is doubled, but the pleasure per “unit” of pain is doubled, meaning four times the pleasure.

What spoils this ingenious idea is that no one, including sadists, really knows other people’s pleasure and pain (or even if they have minds at all). It is the counterpart of Schlesinger’s treatment of physical doubling. How would the sadist know that pain has doubled?

All these examples demonstrate that there are many wildly different hypotheses that are compatible with experience—an
infinite
number, Poincaré said. The scientific method is powerless to rule out these alternative hypotheses. Can we say that a hypothesis like nocturnal doubling is true or false?

Poincaré felt that some of these irrefutable hypotheses are easier to work with but not necessarily truer. Poincaré’s view is distressing to many. Rather than one reality, there are many; you are free to take your pick.

“A reality completely independent of the spirit that conceives it, sees it or feels, is an impossibility,” Poincaré wrote. “A world so external as that, even if it existed, would be forever inaccessible to us. What we call ‘objective reality’ is, strictly speaking, that which is common to several thinking beings and might be common to all; this common part, we shall see, can only be the harmony expressed by mathematical laws.”

S
EVERAL YEARS had passed since Sherlock Holmes retired to the placid life of a beekeeper on the Sussex Downs. His missive (the first) read simply: “The bucolic life does not altogether suit me. How I hunger for mental stimulation! Can you arrange a visit?” I canceled the few appointments on my schedule and booked passage on a train south the next day.