TED日本語 - スティーブン・ピンカー、レベッカ・ニューバーガー・ゴールドスタイン: 遠くまで及ぶ理性

[ "Rebecca Newberger Goldstein" ] [ "Steven Pinker" ] [ "The Long Reach of Reason" ] Cabbie: Twenty-two dollars. Steven Pinker: Okay. Rebecca Newberger Goldstein: Reason appears to have fallen on hard times: Popular culture plumbs new depths of dumbth and political discourse has become a race to the bottom. We're living in an era of scientific creationism,9/11 conspiracy theories, psychic hotlines, and a resurgence of religious fundamentalism. People who think too well are often accused of elitism, and even in the academy, there are attacks on logocentrism, the crime of letting logic dominate our thinking.

SP: But is this necessarily a bad thing? Perhaps reason is overrated. Many pundits have argued that a good heart and steadfast moral clarity are superior to triangulations of overeducated policy wonks, like the best and brightest and that dragged us into the quagmire of Vietnam. And wasn't it reason that gave us the means to despoil the planet and threaten our species with weapons of mass destruction? In this way of thinking, it's character and conscience, not cold-hearted calculation, that will save us. Besides, a human being is not a brain on a stick. My fellow psychologists have shown that we're led by our bodies and our emotions and use our puny powers of reason merely to rationalize our gut feelings after the fact.

RNG: How could a reasoned argument logically entail the ineffectiveness of reasoned arguments? Look, you're trying to persuade us of reason's impotence. You're not threatening us or bribing us, suggesting that we resolve the issue with a show of hands or a beauty contest. By the very act of trying to reason us into your position, you're conceding reason's potency. Reason isn't up for grabs here. It can't be. You show up for that debate and you've already lost it.

SP: But can reason lead us in directions that are good or decent or moral? After all, you pointed out that reason is just a means to an end, and the end depends on the reasoner's passions. Reason can lay out a road map to peace and harmony if the reasoner wants peace and harmony, but it can also lay out a road map to conflict and strife if the reasoner delights in conflict and strife. Can reason force the reasoner to want less cruelty and waste?

RNG: All on its own, the answer is no, but it doesn't take much to switch it to yes. You need two conditions: The first is that reasoners all care about their own well-being. That's one of the passions that has to be present in order for reason to go to work, and it's obviously present in all of us. We all care passionately about our own well-being. The second condition is that reasoners are members of a community of reasoners who can affect one another's well-being, can exchange messages, and comprehend each other's reasoning. And that's certainly true of our gregarious and loquatious species, well endowed with the instinct for language.

SP: Well, that sounds good in theory, but has it worked that way in practice? In particular, can it explain a momentous historical development that I spoke about five years ago here at TED? Namely, we seem to be getting more humane. Centuries ago, our ancestors would burn cats alive as a form of popular entertainment. Knights waged constant war on each other by trying to kill as many of each other's peasants as possible. Governments executed people for frivolous reasons, like stealing a cabbage or criticizing the royal garden. The executions were designed to be as prolonged and as painful as possible, like crucifixion, disembowelment, breaking on the wheel. Respectable people kept slaves. For all our flaws, we have abandoned these barbaric practices.

RNG: So, do you think it's human nature that's changed?

SP: Not exactly. I think we still harbor instincts that can erupt in violence, like greed, tribalism, revenge, dominance, sadism. But we also have instincts that can steer us away, like self-control, empathy, a sense of fairness, what Abraham Lincoln called the better angels of our nature.

RNG: So if human nature didn't change, what invigorated those better angels?

SP: Well, among other things, our circle of empathy expanded. Years ago, our ancestors would feel the pain only of their family and people in their village. But with the expansion of literacy and travel, people started to sympathize with wider and wider circles, the clan, the tribe, the nation, the race, and perhaps eventually, all of humanity.

RNG: Can hard-headed scientists really give so much credit to soft-hearted empathy?

SP: They can and do. Neurophysiologists have found neurons in the brain that respond to other people's actions the same way they respond to our own. Empathy emerges early in life, perhaps before the age of one. Books on empathy have become bestsellers, like "The Empathic Civilization" and "The Age of Empathy."

RNG: I'm all for empathy. I mean, who isn't? But all on its own, it's a feeble instrument for making moral progress. For one thing, it's innately biased toward blood relations, babies and warm, fuzzy animals. As far as empathy is concerned, ugly outsiders can go to hell. And even our best attempts to work up sympathy for those who are unconnected with us fall miserably short, a sad truth about human nature that was pointed out by Adam Smith.

Adam Smith: Let us suppose that the great empire of China was suddenly swallowed up by an earthquake, and let us consider how a man of humanity in Europe would react on receiving intelligence of this dreadful calamity. He would, I imagine, first of all express very strongly his sorrow for the misfortune of that unhappy people. He would make many melancholy reflections upon the precariousness of human life, and when all these humane sentiments had been once fairly expressed, he would pursue his business or his pleasure with the same ease and tranquility as if no such accident had happened. If he was to lose his little finger tomorrow, he would not sleep tonight, but provided he never saw them, he would snore with the most profound security over the ruin of a hundred million of his brethren.

SP: But if empathy wasn't enough to make us more humane, what else was there?

RNG: Well, you didn't mention what might be one of our most effective better angels: reason. Reason has muscle. It's reason that provides the push to widen that circle of empathy. Every one of the humanitarian developments that you mentioned originated with thinkers who gave reasons for why some practice was indefensible. They demonstrated that the way people treated some particular group of others was logically inconsistent with the way they insisted on being treated themselves.

SP: Are you saying that reason can actually change people's minds? Don't people just stick with whatever conviction serves their interests or conforms to the culture that they grew up in?

RNG: Here's a fascinating fact about us: Contradictions bother us, at least when we're forced to confront them, which is just another way of saying that we are susceptible to reason. And if you look at the history of moral progress, you can trace a direct pathway from reasoned arguments to changes in the way that we actually feel. Time and again, a thinker would lay out an argument as to why some practice was indefensible, irrational, inconsistent with values already held. Their essay would go viral, get translated into many languages, get debated at pubs and coffee houses and salons, and at dinner parties, and influence leaders, legislators, popular opinion. Eventually their conclusions get absorbed into the common sense of decency, erasing the tracks of the original argument that had gotten us there. Few of us today feel any need to put forth a rigorous philosophical argument as to why slavery is wrong or public hangings or beating children. By now, these things just feel wrong. But just those arguments had to be made, and they were, in centuries past.

SP: Are you saying that people needed a step-by-step argument to grasp why something might be a wee bit wrong with burning heretics at the stake?

RNG: Oh, they did. Here's the French theologian Sebastian Castellio making the case.

Sebastian Castellio: Calvin says that he's certain, and other sects say that they are. Who shall be judge? If the matter is certain, to whom is it so? To Calvin? But then, why does he write so many books about manifest truth? In view of the uncertainty, we must define heretics simply as one with whom we disagree. And if then we are going to kill heretics, the logical outcome will be a war of extermination, since each is sure of himself.

SP: Or with hideous punishments like breaking on the wheel?

RNG: The prohibition in our constitution of cruel and unusual punishments was a response to a pamphlet circulated in 1764 by the Italian jurist Cesare Beccaria.

Cesare Beccaria: As punishments become more cruel, the minds of men, which like fluids always adjust to the level of the objects that surround them, become hardened, and after a hundred years of cruel punishments, breaking on the wheel causes no more fear than imprisonment previously did. For a punishment to achieve its objective, it is only necessary that the harm that it inflicts outweighs the benefit that derives from the crime, and into this calculation ought to be factored the certainty of punishment and the loss of the good that the commission of the crime will produce. Everything beyond this is superfluous, and therefore tyrannical.

SP: But surely antiwar movements depended on mass demonstrations and catchy tunes by folk singers and wrenching photographs of the human costs of war.

RNG: No doubt, but modern anti-war movements reach back to a long chain of thinkers who had argued as to why we ought to mobilize our emotions against war, such as the father of modernity, Erasmus.

Erasmus: The advantages derived from peace diffuse themselves far and wide, and reach great numbers, while in war, if anything turns out happily, the advantage redounds only to a few, and those unworthy of reaping it. One man's safety is owing to the destruction of another. One man's prize is derived from the plunder of another. The cause of rejoicings made by one side is to the other a cause of mourning. Whatever is unfortunate in war, is severely so indeed, and whatever, on the contrary, is called good fortune, is a savage and a cruel good fortune, an ungenerous happiness deriving its existence from another's woe.

SP: But everyone knows that the movement to abolish slavery depended on faith and emotion. It was a movement spearheaded by the Quakers, and it only became popular when Harriet Beecher Stowe's novel "Uncle Tom's Cabin" became a bestseller.

RNG: But the ball got rolling a century before. John Locke bucked the tide of millennia that had regarded the practice as perfectly natural. He argued that it was inconsistent with the principles of rational government.

John Locke: Freedom of men under government is to have a standing rule to live by common to everyone of that society and made by the legislative power erected in it, a liberty to follow my own will in all things where that rule prescribes not, not to be subject to the inconstant, uncertain, unknown, arbitrary will of another man, as freedom of nature is to be under no other restraint but the law of nature.

SP: Those words sound familiar. Where have I read them before? Ah, yes.

Mary Astell: If absolute sovereignty be not necessary in a state, how comes it to be so in a family? Or if in a family, why not in a state? Since no reason can be alleged for the one that will not hold more strongly for the other, if all men are born free, how is it that all women are born slaves, as they must be if being subjected to the inconstant, uncertain, unknown, arbitrary will of men be the perfect condition of slavery?

RNG: That sort of co-option is all in the job description of reason. One movement for the expansion of rights inspires another because the logic is the same, and once that's hammered home, it becomes increasingly uncomfortable to ignore the inconsistency. In the 1960s, the Civil Rights Movement inspired the movements for women's rights, children's rights, gay rights and even animal rights. But fully two centuries before, the Enlightenment thinker Jeremy Bentham had exposed the indefensibility of customary practices such as the cruelty to animals.

Jeremy Bentham: The question is not, can they reason, nor can they talk, but can they suffer?

RNG: And the persecution of homosexuals.

JB: As to any primary mischief, it's evident that it produces no pain in anyone. On the contrary, it produces pleasure. The partners are both willing. If either of them be unwilling, the act is an offense, totally different in its nature of effects. It's a personal injury. It's a kind of rape. As to the any danger exclusive of pain, the danger, if any, much consist in the tendency of the example. But what is the tendency of this example? To dispose others to engage in the same practices. But this practice produces not pain of any kind to anyone.

SP: Still, in every case, it took at least a century for the arguments of these great thinkers to trickle down and infiltrate the population as a whole. It kind of makes you wonder about our own time. Are there practices that we engage in where the arguments against them are there for all to see but nonetheless we persist in them?

RNG: When our great grandchildren look back at us, will they be as appalled by some of our practices as we are by our slave-owning, heretic-burning, wife-beating, gay-bashing ancestors?

SP: I'm sure everyone here could think of an example.

RNG: I opt for the mistreatment of animals in factory farms.

SP: The imprisonment of nonviolent drug offenders and the toleration of rape in our nation's prisons.

RNG: Scrimping on donations to life-saving charities in the developing world.

SP: The possession of nuclear weapons.

RNG: The appeal to religion to justify the otherwise unjustifiable, such as the ban on contraception.

SP: What about religious faith in general?

RNG: Eh, I'm not holding my breath.

SP: Still, I have become convinced that reason is a better angel that deserves the greatest credit for the moral progress our species has enjoyed and that holds out the greatest hope for continuing moral progress in the future.

RNG: And if, our friends, you detect a flaw in this argument, just remember you'll be depending on reason to point it out.

Thank you. SP: Thank you.

(Applause)