A Moral Reckoning

Transcription

Stanford University (Applause) John Etchemendy: Thank you, Howard. And than you for inviting me to celebrate Class Day with graduates and their families. It's my pleasure to introduce this year's Class Day Speaker, Professor Robert Sapolsky. But before I do that, allow me a word with this year's graduates. Now, you may not remember this, but I was the first person to give you an academic assignment oh so many years ago during New Student Orientation. And proudly, as Provost, I'll give you your last one tomorrow during commencement. I just wanted to have you all know that doing so will be an honor for me, just as being here today is an honor. You'll hear a lot of speeches today and tomorrow, but if there's one thought that I want you to take with you as you leave the farm, let it be this: Know that we are all very proud of you. As Howard said, we hope that you'll remain active in the university, we need your wisdom, we seek it often. We will ask you for your time and support on behalf of students who will follow. I hope you will respond as have generations before you. The affection between Stanford alumni and students, and the close bonds that they create, is one of this institution's greatest strengths. So now let me introduce today's speaker: Robert Sapolsky. The John A. & Cynthia Fry Gunn Professor of Biological Sciences and professor in the departments of biology, of neurology and neurological sciences, and of neural surgery. Professor Sapolsky is one of the world's leading neuroscientists and an expert on stress among humans, baboons, orang-utans and other primates. I understand Professor Sapolsky's family is here as well, and I'd like to welcome his wife Lisa, son Benjamin and daughter Rachel. Thank you for joining us today. No doubt, our seniors selected Professor Sapolsky to give this lecture because he's not only one of the university's most accomplished researchers, but he's also one of our best-known and most enthusiastic teachers. Now, I don't mind at all introducing Professor Sapolsky, but I have a firm policy never to speak after Professor Sapolsky. (Laughter) Through his incredible story-telling ability, Professor Sapolsky has shared his research on the biology of neurons to help us better understand the causes and consequences of stress. He's the author of such compelling books as "Why zebras don't get ulcers", "Monkeyluv", and "A Primate's Memoir: A Neuroscientist's Unconventional Life among the Baboons". He explained his work this way to the Stanford Report newspaper, "Primates are super smart and organized, just enough to devote their free time to being miserable to each other, and stressing each other out." So essentially, we've evolved to be smart enough to make ourselves sick. Now, I assure you that he's right about this; I read Professor Sapolsky's first book, "Why zebras don't get ulcers", nine years ago in the hospital, recovering from a bleeding ulcer. (Laughter) It's true. Now I think I've become much more zebra-like since then. His engaging tales of baboons, their social lives, and his annual adventures in Kenya, studying them, have been described by book reviewers as "brilliant", "exhilarating", "funny" and "disarmingly emotional". In fact, a New York Times reviewer once called him a cross between Jane Goodall and a borscht belt comedian. (Laughter) Now, he's also the subject of a recent National Geographic Special, called "Stress: Portrait of a Killer", which vividly reveals how lethal stress can become. Professor Sapolsky was raised in New York City, where he frequented the Museum of Natural History. He's a graduate of Harvard and Rockefeller universities, a recipient of a MacArthur Foundation fellowship, and a Research Associate at the National Museums of Kenya. He's been a faculty member at Stanford since 1987, and has won many of the university's highest teaching awards, in fact, tomorrow, he will receive yet another: The Walter J. Gores Award for excellence in teaching. You're about to see why. Please join me in welcoming this year's Class Day Speaker, Professor Robert Sapolsky. (Applause) Robert Sapolsky: Well... This is actually really weird. I gotta tell you: Never in my wildest dreams, never in my most delusional of pre-adolescent fantasies did I ever think I would be applauded by a large audience in a basketball stadium. (Laughter) So... Thank you, Stanford, for letting unlikely dreams come true. Okay! So... to start out, as John noted, I'm a neurobiologist/primatologist, and I've spent part of each of the last thirty years studying wild baboons in East Africa. And if you spend enough time around something like baboons, you start to look at humans differently. For example, you find yourself paying a whole lot of attention to other guys and how big their canines are, (Laughter) thinking comparatively, or you look at somebody's rump and you wonder how hard it would be to anaesthetize them with a blowgun dart there... (Laughter) Or you look at somebody and you wonder: "Well, is this a monogamist or a polygamist primate", and you start to look at humans in different ways. And what I thought I would do today is talk a bit about how one, thus, makes sense of humans in this context of "We're a primate, we're just another species." And it will hark back to a famous quote from some evolutionary biologist who said that all species are unique, but humans are unique-ier -- or something like that. This may not be an exact quote, but what I'll focus on here is what is it that makes us not so unique-ier, and ways in which it does. So starting off... Okay, I thought I would kind of see what I'm talking about today. So starting off, the first thing to emphasize is, if you want to understand what we're about as a species and what makes us unique, the first clear punchline is: It ain't gonna have much to do with our genes. It's not going to have (to do) with our neurons and neurotransmitters, take us, take a fruit fly, and we've got almost all the same genes in common. We're not humans because we've invented a different type of brain cell, a different type of brain chemical, we're the same basic building blocks as even a fruit fly, that's not where are uniqueness is going to come from. And as we try to make sense of what we are as a species and where we fit into the animal world, we have a few challenges in making sense of that. The first challenge is: Dealing with circumstances in which there's nothing different about us whatsoever. We're absolutely like every other species out there. Let me give you an example. You are a hamster. You're a female hamster. And if you're a female hamster what you do is you ovulate every four days. Okay. So you're sitting there ovulating every four days in your cage and some scientist now sticks another female hamster in the cage with you. And over the next couple of weeks what will happen is, both of you will start lengthening your ovulatory cycles until after about three weeks or so, synchronizing them, you will both ovulate within about a half hour of each other. Unless they now take a male hamster and put him in the cage with you, at which point you'll all desynchronize your cycles. It's totally cool that it works this way, it works all by olfaction, pheromones, you can show this with some really low-tech experiment, like, you can hold the hamster's nose shut for three weeks and she doesn't synchronize her cycle. (Laughter) Or you could do something really elegant, like don't actually put the male in there, put the male in another cage and pump the air from that cage into yours, and it's the same thing, and what's most amazing of all is, it's not random which female synchronizes the other. It's the socially dominant one. So this is completely understood, and in fact, you could show this in dogs, in cats, in cows... Apparently, if you live in Iowa, you can go to a 7-11 and buy a can of like pig synchronizing ovulatory spray, and go spray it-- I've no idea why you would want to do this, because... (Laughter) Never once in Brooklyn did we try to ovulate our pigs on schedule. But it's that well understood! And what is extraordinary is: It works exactly the same way in us, where it's called the Wellesley Effect, (Laughter) named after Wellesley College, demonstrated in 1970 during freshman year over the course of the year, female freshman roommates synchronize their cycles, except for women who had close intimate relationships with males, and it's all done with olfaction, and what's the most amazing thing of all is it's not random who synchronizes whom, it tends to be women who are more socially extrovert and dominant, and this is well-known enough that when I was in college, people would sit around the dinner table and say stuff like: "When we roomed together this summer, I had her synchronized by August 1st." (Laughter) This is what biologists think like. So, some of the time what is the challenge, is recognizing there's nothing fancy about us at all, we are just a basic off-the-rack mammal. Now, some of the time, with the challenges, is recognizing that we've got the same basic building blocks and plumbing in there, but we use it in ways that are unprecedented. And let me give you an example of that. So you got two humans, and they're taking part in some human ritual, they're sitting there silently at a table, they make no eye contact, they're still, except every now and then, one of them does nothing more taxing than lifting an arm and pushing a little piece of wood, and if it's the right wood and the right chess grandmaster is in the middle of a tournament, they are going through six to seven thousand calories a day, thinking. Turning on a massive physiological stress response, simply with thought, and doing the same thing with their bodies, as if they were some baboon that's just ripped open the stomach of their worst rival, and it's all with thought, and memories, and emotions, and ima-- and suddenly, we're in a realm of taking just plain old nuts and bolts physiology and using it in ways that are unrecognizable. But some of the time though, the challenge is: We're dealing with something where we are simply unique, there's no precedent out there in the animal world. And let me give you an example of this, a shocking one. Okay. You have a couple. They come home at the end of the day, they talk, they eat dinner, they talk, they go to bed, they have sex, they talk some more, they go to sleep. The next day, they do the same exact thing. They come home from work, they talk, they eat, they talk, they go to bed, they have sex, they talk, they fall asleep. They do this every day for thirty days running. A giraffe would be repulsed by this! Hardly anybody out there has non-reproductive sex day after day and nobody talks about it afterward. (Laughter) And when you look at this, what the challenge there winds up being, is recognizing, some of the time, if you want to understand what we're up to, there's simply no precedent. So now, beginning to look at ways in which we're still unique, -- some of the challenges now are no longer very challenging. Back in the 1960s, Jane Goodall first demonstrated that chimps make tools, and generations of social anthropologists took early retirement at that point because we were no longer the only species that's a tool maker; we're accustomed to that by now. That one's easy, that wasn't threatening our sense in who we are. But there's much more subtle realms these days where we not only have to question what makes us human, but where we get insights as to whether or not we are all that unique. A first example. The realm of aggression. Back every single one of those Mutual of Omaha specials, at the end there'd always be the deep voice saying: "We are the only species that kills", and that turns out to be wrong. Lots of other species kill, they kill members of their own species, they kill them in anger, they kill them in cold blood premeditation, they kill them strategically, in ways that would make Machiavelli proud, they do it to each other's infants, they do it competitively, advantageously -- we're not the only species that kills. Just to give one example of this. This was a male who had joined one of my troops of baboons a few weeks earlier, and the only way to describe this guy was he had horrible political skills. And we was hassling all sorts of high-ranking guys he should not have been messing with, and one morning, this is what was left of him. And in the thirty years I've studied male baboons, the leading cause of death in male baboons are male baboons -- we're not the only species that kills. In addition, we're not the only species that kills in an organized manner. This is what's called a border patrol, a group of chimps in a group that have gotten together and they're patrolling the edge of their territory, and if they encounter a male from another group, they will attack and kill them. And it's documented by Goodall in at least one circumstance, it's things like this, a group organized enough to do this systematically, and kill all the members of a neighboring troop. So we're not just the only ones that kill, not the only ones who kill in an organized way, but this is some protoversion of genocide, we're not the only ones who do this either. So what about us then, and our aggression? And what you see is some of the time, we can just cudgel someone over the head like any good old primate, but some of the time, we're doing stuff that's unrecognizable, we can do nothing more physically challenging in our aggression than pulling a trigger, or dropping a bomb from 30,000 ft, or looking the other way. We can be passive-aggressive, we can damn with feigned praise, we can do all sorts of subtle things. Let me give you an extraordinary example of a way in which humans can damage each other for which the world has never seen the lights of before. Every day, outside of Las Vegas, there are people who get up in the morning and they are rushing off to work, and their spouse reminds them to pick up the dry cleaning on the way home, and they say goodbye to their kids and they rush out and they get caught in traffic and they're all anxious they're gonna be late at work and they luck out and get a good parking spot and get to work and sit down in a flight simulator, and what they spend the day doing is operating a drone bomber in Iraq that drops bombs and kills people. This is at Nellis Airforce Base, people sitting there, spending their workdays operating drone bombers on the other side of the world. And at the end of the day, having finished your day doing that, you get up and rush off because you want to be there in time for your daughter's ballet performance and you hug her afterward and you can't believe it's possible to love someone that much, and the next day, you sit in this dark room and kill people on the other side of the planet. And there's nothing out there in the animal world that has a precedent for that. And not surprisingly, apparently, the rate of psychiatric problems among people who spend their days doing this is also unprecedented. So, in some ways, there is no precedent for that realm of us. Okay, what else? Theory of mind. This is a very trendy term among psychologists. Theory of mind: the first time you realize that somebody else has different thoughts than you. Somebody else has different information, this is a big developmental landmark. The first time kids get theory of mind, it typically happens between ages 3 and 5. My wife and I tested, our kids hit it at 3.2 years of age, so we're very proud of them. (Laughter) So, theory of mind is great, this is wonderful and this is a defining thing of humans and it turns out we're not the only species with some rudimentary theory of mind. Recent experiment here with some chimpanzees. Take two chimps, and there's a room in front of them, they're both in a cage or something on either side, and in the middle, there is a screen. And the screen can either be transparent or opaque. On one side is this low-ranking schnook of a baboo-- a chimp, and somebody comes out and puts a ba--, I'm thinking baboons today for some reason -- and puts down a banana on this side of the screen. And in one case, when the screen is opaque, this chimp sees the baboo-- the banana, and the high-ranking chimp on the other side cannot. Put a transparent screen, and both of them can see it. Now you release them, they both come out, and the question is, there's this low-ranking guy who knows there is a banana there, does it go for it? And it uses theory of mind. Here's what goes on. The chimp thinks: Okay, if the other big, high-ranking guy didn't see the banana because the opaque screen is there, I'm gonna go grab it. If the screen was transparent, I'm not gonna be even bother because he's taking it away from me. If he's lower-ranking than me and he saw it, it doesn't matter, I'm still gonna get it, he understands the other chimp has information that he does not. The other chimp thinks differently. This is theory of mind. And this is extraordinary. What no other species has, however, is called secondary theory of mind, which is when you understand that that individual has information that that one doesn't, and thus that one thinks this one is doing this, but it actually doing that, and no other animal could sit through something like a performance of Midsummer Night's Dream and understand what's going on there with whom. (Laughter) We are the only ones who'd be willing to spend an evening doing that and have a clue what was happening there, so, we are alone in that realm as well. What else? More examples. The Golden Rule, the iconic way in which we go about our moral systems, and every culture out there having some variant on it, it being very interesting whether the variant is "do unto others as you would have them do unto you", or is it "don't do unto others as you would not have them do to you", and I suspect that tells you something about a basic pessimism of the latter cultures. But this is universal. This is all over the place, this is us. And it's sufficiently us, that there's actually people who spend careers doing highly complex mathematics on ways to optimize game playing, to optimize circumstances of golden rule, and these are people who inform economists and war theorists and diplomats, game theory stuff, and there's all sorts of ways in which these strategies are optimized, the one, the classic one, that was shown by an economist named Robert Axelrod is the incredibly simple strategy for going about competing with somebody else, the tit-for-tat rule. You start off cooperating, if they cooperate with you, you continue cooperating, if at some point they stab you in the back, the next time, you stab them in the back in return. And if they go back to cooperating, so do you, and this optimizes a whole competitive strategy. Now this was worked out mathematically in the 70s, and the zoologists at this point looked at it and said: "Huh! I wonder if there's any animals out there who also use tit for tat optimization strategies for when they cooperate and when they compete." And it turns out we're not the only ones with that, either. First example. Okay. Horrible, vicious, nightmare vampire bat creature that haunts our nightmares. In actuality, when a vampire bat is drinking up some cow's blood, it is being a very good mommy, because what she's doing is getting blood in order to feed her babies. She's not actually drinking the stuff. Vampire bats store the blood in their throat sack. They fly back to their nest and they go to the babies and they disgorge the blood to feed their babies. Very interestingly, these are big social communal nests. They also disgorge blood to feed everybody else's babies. It's a whole communal feeding system, they all cooperate. Make the bats think that one of the females in there is cheating, is not fulfilling her social contract. She comes out of the nest there and you net her and you take hold of her and you take a syringe full of air and you pump up the throat sacks so it's nice and big and full and distended, and push her back into the nest, and everybody's sitting there sitting: "Oh my god, look at that throat sack, look how much blood she's got in there, and she's not feeding my babies!" And the next round, nobody feeds her babies. They tit-for-tat her back. They do some version of the golden rule. Now, bats are not some of the smartest folks around, but you can see the same thing in fish, in stickleback fish. Here's what you do. You take advantage of their extraordinary cognition. You take a stickleback in a tank and make him believe that he is being attacked by another fish. You put a mirror up against the side of the tank there. (Laughter) So of course, he's immediately lunging at it and all of that, and saving the territory and all the nationalism and territorial waters and that kind of stuff, and fighting off this invader. Now make the stickleback think that he's got a cooperative partner. Take a second mirror and put it up perpendicular to him. So everytime he's moving forward he's seeing this other fish there doing the same thing, and he's saying: "I don't know who this guy is, but he's great, it's another guy attacking there, and we're totally synchronized, yay team!" And now, now make him think the other fish is cheating on him. Take the mirror and angle it this way so the image is deflected backward, so he seems to be further back, and he's saying: "That son of a bitch, I can't believe it! Here we are, being attacked and oh yeah, he's pretending to go but I see he's hanging back there, I'm blistering my lips here on this glass and he's just hanging back there." And the next time he sees his image, he doesn't attack it. He believes he's tit-for-tatting the guy. So we are not alone in this whole realm of wanting to do unto others and don't do unto others, and taking tit-for-tat revenge. But what is unique about us is our capacity to have not do unto others as you would have them do unto you, but to understand circumstances in which somebody else's reward is not the same sort of reward that you would have. And there are very few species out there who would understand what this one is about. "BEAT ME," SAID THE MASOCHIST. "NO," SAID THE SADIST. Understanding that, we might all have very different values of what things we are rewarded by. Okay. So we are somewhat unique there. Next domain. Empathy. Empathy as defining of who we can be as a species. Our greatest moments show aspects of empathy. It is the thing that makes us morally bound to each other, and what has become clear is despite what anthropologists and theologians and who knows what else have said forever, we're not the only species that shows elements of empathy. Example of this. And this was work done by a wonderful primatologist named Frans Dewaal. And what he did was, in studying chimps, demonstrate the following. Okay. You have a circumstance. You've got some chimp who does something ridiculously imprudent -- He goes and he hassles some big high-ranking guy, threatens him and gets utterly pummeled. In contrast, you've got some poor chimp sitting there minding his own business, and a big high-ranking guy in a bad mood pummels him for no reason whatsoever. First circumstance: The guy asked for it. Second circumstance: He's an innocent bystander. And what Dewaal shows is in the hour after each of these guys are pummeled, the innocent bystander guy is like five times more likely to be socially groomed by everybody else. This guy was asking for it, this guy was a victim, let's go and try to make him feel better. And that's pretty shocking, that is understanding motivations, that is understanding victimhood, and that is being moved as a chimp to try to make the victim feel better, because you take a chimp who's upset and the best thing to calm them down is socially groom them, something looking like the rudiments of empathy. So we're not alone in that. But where we are alone is just the extraordinary directions where we could take that empathy. An example here. Okay. Look closely at this picture, and almost certainly you are recoiling somewhat. This is a dog whose foot has been caught in some trap to the point of necrotically the paw falling off. This is horrible. We look at this and we are feeling empathy for this dog. We are feeling how painful and frightening it must have been for this dog. We are feeling empathy for a member of another species. This is unheard of! But we could take this even further. Here, we take an iconic picture of the 20th century and the misery we can impose on each other during this past century, and we look at this picture and we can think about the horses that were in Guernica as the fascist bombs fell, and the terror of them in burning barns, and we're sitting here feeling pain and empathy for that horse. And that horse is a painting! But we could take it even one step further. This is from a painter named Franz Marc, a German expressionist, who, like many of his generation, was basically destroyed by the trench warfare in World War I. And this was painted shortly after that. A painting called "The Fate of the Animals." And what you have here is sheer utter chaos breaking out all around, no doubt the emotional viscera of what World War I was about, and in the center an animal baying at the moon amid the terror of this chaos, an animal of a shape, appearance, color that does not even exist on earth, this is a purely imaginary animal, and we sit here, and understanding where this came from and what he had experienced to paint something like this, we're not feeling sorry for that animal, we're feeling sorry for the animals, for all of the innocent victims. We are taking empathy to a realm that no other species can imagine. So, we're not so common in that domain either. Next. How we go about reward. This brings in a little neurobiology. The involvement of a neurotransmitter or brain chemical messenger called dopamine. Dopamine is all about reward. You do not want your brain to run out of dopamine or else you will become clinically depressed. Cocaine works on the dopamine system, all sorts of euphoriants work on dopamine. Dopamine is about reward. At least, that's what people used to think. And they used to think it would work as follows. You've take a monkey and you've trained it in some tasks. You give it a signal, a light goes on in its room, and that means, "Okay, a task is about to begin." And the monkeys learn that if it now does this task, whatever the work is, it will then get a reward after some delay. And what everybody assumed was, what dopamine was about, was, once you got that reward, dopamine levels went up. Dopamine was about pleasure, reward, that pot of gold at the end of the rainbow, all that sort of thing. Turns out that's not what dopamine is about. It looks like this instead. You've got this monkey trained to do this task and the signal comes on saying, "Okay, we're starting one of these sessions again," and then the dopamine goes up. What is this about? This is not pleasure of getting the reward, this is "I know how this one works, this is great, I'm all on top of this. I know exactly what to do, piece of cake, I've got this under control, I'm on this one." It is not about reward, it's about the anticipation of a reward. And in fact, if you block that dopamine rise from occurring, you don't get the work. It's not only about the anticipation of reward, it's about the goal-directed behavior it is able to fuel. A very subtle additional piece of it, a wonderful study done some years ago, where you take this scenario, okay, the individual, the monkey, does the work, and after the delay it gets the reward 100% of the time. Now, instead, in this setting, it gets the reward only 50% of the time. What happens now when that signal comes on? What it looks like is this: You switch over to 50% and the dopamine levels explode through the roof there. What have you just done? You've introduced the word "maybe" into your equation. And that is reinforcing like nothing on earth. That signal comes on and that monkey's sitting there saying: "Piece of cake, I'm on top, but I'm such a screw-up, and I'm not gonna be-- oooh, but today, today, I'm gonna be, naah, it's not gonna work out..." And you just have him teetering there on this fulcrum and that is pushing dopamine out like there is no tomorrow. Just to show that, now, instead of a 50% reward rate, give the monkey either a 25% or a 75% reward rate. Totally opposite things! This one is bad news, this one is good news. What's the one thing they have in common? Both reduce the unpredictability, both lower the dopamine surge to the same extent. Take a monkey and there's nothing more addictive out there than the notion that there's a reward lurking out there, and it's a maybe. And what some of our best social engineers, many of them making a good living in Las Vegas, learn how to do, is how to turn what seems like a 50% reality of reward to make it that [salience] when it's one tenth of a hundredth of a percent of a chance of reward, how to make one get that dopamine surge and get that goal-directed behavior out of there. So, it turns out that brain chemistry works exactly the same way in us. In us, dopamine is about the anticipation of a reward, uncertainty boosts it up further, it drives the work needed for the reward, but what's unique about us, what's the difference, is the lag time between the work and the reward. How long we can hold on driven by that dopamine surge to pump out that work in order to get the reward, and we all know this scenario where you interview really, really well for your preschool, and as a result, you get into a good school and a good high school and you study hard and you get a good GPA and get into a good grad school, get a good job and eventually, get into the nursing home of your choice... (Laughter) And, what we've got here is this astonishing human capacity to hold on. And what we have that is completely unprecedented is the ability in some ideological and some theological systems to hold on even after you are gone. And a world in which you have a reward that comes in an afterlife and a world in which you are willing to put up with the most egregious versions of pain in the name of holding on, holding on, a world in which unto the generations after you and the sins upon your children, and there's nothing like that out there in any other species. Final domain. Domain of culture. Now, if you're a primatologist, up to about ten years ago, if you ever said the word "culture" in front of other primatologists, they instantly took your tenure away. Because assured you were obviously not serious in anthromorphizing. These days, there are two words that are the trendiest in primatology, the first is culture, the second is personality. These are both very relevant to non-human species. Culture as defined as the non-genetic transmission of behavioral styles to a next generation, we are not the only species that has culture. Chimps pass on styles of making tools, there's 27 different variants of regional behavioral differences in different chimp populations that are passed on as culture. A number of years ago in my baboons, I found an interesting example of this as well. And this was a troop where for very complicated reasons having to do with proximity of humans, half of the males in this troop were killed by humans, and it happened that these were the most aggressive males in the troop. And what you were left with was a very unique situation where there were twice as many females as males, and the males who survived were those very affiliative nice guys, and this produced a completely different social atmosphere in this troop, one where there was far less aggression, everybody getting along a lot better, and here's one example of this. If you are a baboonologist, what I show you here is a lot stranger than if you discovered that baboons could fly or were photosynthetic or something. What we have here are two adult male baboons grooming each other. Male baboons do not do this, except in this troop. And as new adolescent males join this troop, transferring in from elsewhere, they learn to do this. There is transmission of this cultural style. So we're not the only species that can have culture-building tools and microwaves, we're even not the only one that has cultural transmission of entire social atmospheres. So what's unique about us, what is obvious is just the broke, Byzantine, complex magnificence of human culture and what we're able to do with that, and we see here -- other species would wither in envy at a photograph like this, knowing that we are able to do stuff like this. Okay. So what we've got now are all these examples, where, I think we've got categories of basic building blocks: aggression, empathy, theory of mind, but where we're doing them in ways that are completely unprecedented. But then we move into this final domain, where we do things where there is simply nothing else like it in the animal world. And there's lots of examples of it: Our sexual behavior, our communication, our language use. Let me give you an example though, the thing that I think is most defining and most importantly, who we are. And it could be stated in this fairly abstract sense here, of a circumstance where the less it is possible that something can be, the more it must be. What do I mean by this? Let me make this a little less abstract here, and frame it within a certain type of theology with a whole notion of not only being able to hold a contradiction in your head, but the very contradictory nature of it is what makes it vital and essential and a moral imperative. Let me give you a more explicit example of it. This is a catholic nun named Sister Helen Prejean, and what she has done is spent her entire life ministering to the needs of men on death row in a maximum security prison in Louisiana. Some of the most frightening nightmarish humans who have ever walked this earth, some of the most deplorable people out there, and naturally, endlessly, she is asked: "How can you spend your time doing this with people like that?" And she has always had a very simple answer, which is: "The less forgivable the act, the more must be forgiven. The less loveable the person is, the more you must find the means to love them." And as a strident atheist, this strikes me as the most irrational magnificent thing we are capable of as a species. And it's in that realm that we go so far past the fact of the ways in which we can do special things with theory of mind and empathy and culture and all of that, and it's this simple trade that moves us, we are not just the unique-ier than any other species out there, we are the unique-ier-est, simply because of this property of us. And this one does not come easily. And on a certain level, the harder this is, this contradiction, to take the impossibility of something to be the very proof that it must be possible, and must become a moral imperative, the harder it is to do that, the more important it is. And that winds up being very relevant to this circumstance here, and probably a good spot for closing. You guys, as of tomorrow around noon, are officially educated. And as part of your education, what has happened is you have learned something about the ways of the world, how things work, you've learned the word Realpolitik, you've had your eyes opened up, you've wised up, and one of the things that happens is that when you've wised up enough, there's a very clear conclusion that you have to reach after a while, which is: At the end of the day, it's really impossible for one person to make a difference. And thus, the more clearly, absolutely, utterly, irrevocably, unchangeably clear it is that it is impossible for you to make a difference and make the world better, the more you must. You guys are educated, you are privileged, you are well-connected, you are enormously lucky if you are sitting here at this juncture, and thus, what that means is, there's nobody out there who's in a better position to be able to sustain a contradiction like this for your entire life and use it as a moral imperative. So do it. And good luck, and have good lives in the process. (Applause) transcript: [email protected]