So book seven of Plato's Republic opens with an unforgettable image, the image of the cave and Plato's leading character Socrates begins by inviting his interlocutors to, to imagine the situation. So I'm going to ask you to begin by imagining before I show you some modern renderings of the image. So imagine Socrates says, human beings living in an underground cave-like dwelling with an entrance a long way up. They've been there since childhood with their necks and legs. Fettered able to see only in front of them because their bonds prevent them from turning their heads around. So here is a modern portrayal of the story. So as you can see, the prisoners are trapped in a world of artificial light. And in fact, all they can see are the shadows that are cast on the wall. So you can see the shadow of the horse there, which is cast by the artificial fire light. So in this rendering, you can see that the light of the sun never actually reaches where the prisoners are trapped. And what this means is that what they see are these shadows cast by the artifacts that puppeteer like manipulators carry around behind their backs. So you can see the puppeteer like manipulators there in the blue garments. And so in this world says Socrates, the prisoners would in every way believe that the truth is nothing other than the shadows of those artifacts. And the, the manipulators and the artifacts are the images produced by saws. So they're the images that tell you what to aspire to, what, what in what ways you can earn honors, recognitions, and rewards. And those are all going to go to the people who are best at spotting shadows, not to anyone who might have been enabled to break their bonds and start to seal, see what's real in the light of the sun. So here is another image of the cave. This is a, um, 16th century image. Um, and you can see on the right are the prisoners on the top of the wall are the, um, uh, manipulators and the artifacts. And then out to the left are the people who are starting to be able to escape the cave. And all the way on the left, you can see the people who've managed to get out and they're strolling around doing philosophy in the light of the sun. Now, this image has often been read as a parable about the inevitable woes of mortal life, as if Plato were portraying human beings trapped in a veil of tears whilst on earth to be freed only in a transcendental afterlife. But in fact, Plato's Socrates introduces the whole story as what he calls a comparison to the effect of education on our nature. So Plato's Cave is not the inevitable mortal abode, rather it's the city in the sense of the political community. It's any polity in which we grow up and are educated, which fundamentally shapes our appetites and our aspirations. It's the polity that shows us those artifacts that tell us what we should desire, what we should try to do. And so it's every polity. The cave is every polity that's organized around fundamentally flawed assumptions. So the misinformation that's portrayed there is not occasional malpractice. It's pervasive delusion. It shapes everything that citizens are brought up to believe and desire. So what cave might we be trapped in today? Well, for starters, we might ask the same question about Plato and his contemporaries in terms of what assumptions they took for granted that might today look to us like deep mistakes. Now in lecturing this year at Gresham on the theme, the political imagination, ancient Greek ideas I've so far said relatively little about the stark fact that ancient Greek polities were what historian Moses Finley called slave societies. Their economic development, political participation and cultural achievements were all built on the backs of enslaved people, many of them captured in war. And here we have an image of an enslaved boy. This is a vase from the fifth century, BCE. So about the time of, um, Plato's early adulthood. So the Greeks were trapped in a, in a cave that took slavery for granted. Now, slavery was a fate that everyone dearly wished to avoid for themselves as the 19th century escaped slave, the orator and statesman Frederick Douglass would later reaffirm powerfully. And here's who proclaimed in 1852. There is not a man beneath the canopy of heaven that does not know that slavery is wrong for him. But as Bernard Williams argued in his book, shame and Necessity, the Greeks overwhelmingly saw no alternative to relying upon slavery as a mode of organizing society in general. So this was the cave in which they were trapped. But you can see that that was not a natural or timeless fact. That was a social fact. It was a fact about the polity, the polities in which they lived. And it's a social fact that since has changed, we no longer think it's right or reasonable for people to organize their appetites aspirations and assumptions around seeking to have slaves. The honors recognitions and rewards that most societies offer today are no longer bestowed on those who win wars to enslave the defeated survivors. But the opposite, we would give honors to those who fight against modern slavery, not those who seek to impose it. So in that sense, we are no longer in the same cave as the ancient Greeks. And here again is another, again, the same image. Um, another look at this image of the cave. Now at this point, you may again be wondering why am I talking about slavery when this lecture was supposed to be about climate change? Well consider this comparison advanced by several historians between the energy produced by enslaved humans in human history and the energy produced by fossil fuels. So dependence on fossil fuels, like dependence on enslaved people, has in the words of Jean Francois mou freed their owners from daily chores. And so it's provided them again in moose's words with the leisure to read and write, perform arts, get informed and participate in politics. Other historians have developed the concept of energy slaves as a measure of the kind of energy that machines most of them fueled by fossil fuels have provided us. So John McNeil estimated that in the 1990s, for example, each person alive on average, of course there were great, there was great variation, as he said, deployed about 20 energy slaves, meaning 20 human equivalents working 24 hours a day, 365 days a year. Now, of course, the moral wrong of slavery is a categorical wrong of a unique kind. And even we see here even machines don't want to be slaves, right as is depicted in this image. So the comparison only goes so far. But while this comparison of fossil fuel emissions and the machines that they power to human slavery may be a startling, even a shocking way to think about climate change, I think that's the kind of shock that Plato's image of the cave was designed to produce. Because again, the cave was asking us to consider that the bedrock assumptions on which our society is founded may be rotten to the core. So it asks us to consider that the seeming value of economic growth that allows net carbon emissions is actually a net harm. It's doing damage not social good. And I would remind us here of a message given, uh, recently on this stage by Miles Allen, the Frank Jackson Foundation, professor of the environment here at Gresham, he pointed out that from a climate change perspective, what we should most be concerned with is net emissions. So the net carbon that's added to the atmosphere as opposed to that which might be safely captured and stored. And so it's that net carbon emissions question, um, on which we want to focus. So from the standpoint of the cave denying the significance of these net emissions looks like refusing to face what is true and valid. So one more image of the cave insofar as we are clinging then to the comforts and familiarities of our current way of life with its fossil fuel infrastructure. Are we not trapping ourselves in a modern version of Plato's Cave? All the ways in which we think to achieve advantage and preeminence to satisfy our appetites and desires are like those artifact, those artifacts, they're artificial. They, they don't hold up well, they're mere shadows, um, compared to the light of the sun. Now in Plato's story, the question of how easy it would be to escape the cave is actually presented in a double-edged way. And this image helps us to see it. So in one way, the cave is depicted as almost hermetically sealed. No sunlight at all gets into where the prisoners are held. It's only by traveling arduously upward that anyone can start to see the light. But in another way, in another moment when he reflects on the moral of the story, Plato's character insists that the power to learn is present in everyone's soul. And so the role of education is to redirect our gaze upward to the truth. And you can see that here it looks like you could just turn around and start traveling upward. So in this way, it seems as if maybe the cave actually is more open to light than it might appear in this way. The moral would be akin to the film that some of you may remember don't look up, right? So in that film, an asteroid is hurtling towards the earth and that sparks a movement of political denial. This isn't an image from the film, but it captures that movement of denial, right? One person trying to stop the other from seeing what's actually looming in the sky. But the message of the film is that it's still in our power to kind of tear those hands away and look up, even though just as in Plato's story, there are these social and political pressures conspiring to prevent many people from doing so. So if we think about those two sides of the cave story, to what extent are we sort of desperately trapped? And to what extent is it in our power to start to move outside it? We can see that the paradox of our situation today is that actually much scientific light about the true nature of reality is actually getting in to our current society, and yet people are still somehow paralyzed or resistant to action in response to it. So when I first wrote about climate change in the cave in a book called Eco Republic, I was focused on the cave partly as sheer climate change denial. But of course now I think we're in this even stranger situation where many people do acknowledge the need for urgent action. They recognize the truth, but they're still strangely held back from the radical reconfiguration of society that inadequate response would require. So this is why in this lecture, I want to invite you to consider the cave image from the perspective of three questions. And this is my agenda now for the rest of the lecture. So first of all, we're going to look at the what, what is it that we might come to see by leaving the climate change cave? And we'll look at Plato's account of that as we go. Then we'll move on to the how, how might people be persuaded to leave the cave? And and then thirdly, and finally we'll look at the question. If not, what if some people refuse to leave in that case? Is it justified to tell them what Plato elsewhere in the republic called noble lies? Should we lie to them to either force them out of the cave or at least enable us to get other people out even in the face of continued denial by some? So these are the three cave questions, um, that I want to ask about climate change. So first of all, the what, what is the basis for ethics outside the cave? So in Plato's Republic, we're told that the form of the good is the most important thing to learn about because that's what makes everything become useful and beneficial. And what's striking about this is that Plato observes that every soul pursues the good and does whatever it does for its sake. But that's true even when we make a mistake, even when we're wrong about what is actually good. And that's because we're still seeking what's really good. So to use a platonic example, we can think about medicine, right? If, if I'm going to take medicine, I want it to be good medicine, not bad. If I learn that I've been taking fake or faulty medicine, I'm going to feel cheated or alarmed. So good medicine produces real benefit, which bad medicine cannot. And it's interesting that in the Republic Plato draws a contrast between for example, what's beautiful or even just he says, many people actually are satisfied to appear just to present a beautiful facade. As long as we can sort of get away with it, we're happy just to have the facade. In fact, it might be better off if we can appear just if actually sort of secretly cheat. We might think we'll do better in that case. But by contrast, goodness is something that we don't want to avoid in that way. We don't want, we don't want bad medicine, bad food or bad friends. We instinctively want what's truly good. Now Plato then further develops this idea in terms of the idea of the form of the good. And here I want to follow the work of the late philosopher, um, from the University of St. Andrew's, Sarah Brody, who wrote an important work studying Plato's idea of the form of the good. And what she wanted to emphasize is that the form of the good, which again might sound like esoteric platonic metaphysics might sound like something we could never possibly understand or come to know. What Brody suggested is really what it is, is just interrogative mode. Plato's form of the good is a way of asking whether anything is good. It's really just trying to always get us to ask that simple question. So let's try out Brody's interrogative approach to goodness and apply it to economic growth in relation to climate change. So economic growth has been a presupposition of politics in our modern cave, right? The assumption is that economic growth is a good thing, but if we interrogate that assumption, what we'll see is that we need to make it compatible with sustainability, with getting ourselves on a quick enough path to net zero. So if we measure growth in the wrong way, actually it may not be what's truly good. So as many economists have pointed out, for example, the measure of gross domestic product per capita GDP, we'll value the product of carbon polluting industries. So GDP is not an adequate measure of what's truly good because it's not going to capture the harm that carbon pollution can do. So Plato gives us this beautiful image that we should actually instead think of growth on the model of plants, right? And this is where he connects the image of the good again, to the image of the sun. Plants ultimately are not going to grow down there in the cave. If they're only exposed to firelight, they'll eventually shrivel and die. They can only grow if they're exposed to the illumination of pure sunlight. And this was Plato's use of the metaphor to say, we have to look for what's truly good, not what our diluted economic standards have told us is good. So growth has to be meaningful, not an anarchic cancerous sprawl. And in another platonic dialogue, the gorges, another character contends wrongly that growth is an unbounded process of consumption, as if the way to be happy is just to stuff in as much as you can. And we all know that that won't lead to true health. So the what here is giving us this image that what we need is a true image of what growth is, not a shadow, um, but rather an understanding of growth that's limited and balanced in light of the, the, the reality of, um, what sustainability requires. So that brings us to the second question, the how. So how do we persuade people to let go of the seeming certainties of the cave that they're still clinging to? And I think we can actually turn that question around and turn it on ourselves. And I include myself very much in this because many of us like to think that we are woke, we are liberated, we are out of the cave of climate denial, we get it. But are we really acting in accord with that knowledge or are we sort of half knowing it but really still acting according to those shadowed paradigms? And here I have to share a recent experience that I had myself. So I was thinking about this lecture and I was looking things up on in Google Scholar and I came upon this statement to know is to act. To act is to know. And this was in an article about climate change, um, by a distinguished climate scientist, someone whose work I'd drawn on in the past. And that statement struck me as an important mantra. I think this is actually a deeply platonic thought because if we don't act on our purported knowledge, in what sense do we really know it? And if we do really truly know, why wouldn't we act? So I was very excited when I came upon this statement and I clicked on this article. I thought, yes, this is going to help me to build this lecture only to discover that actually this sentence was put forward by Mike CU in this article as a summary of my own book, which he had read. So in one way, this was very exciting to me, but in another way it kind of showed me I didn't even really fully understand what I myself had been arguing in this book. I hadn't seen that full argument. I wasn't fully out of the cave in my own understanding of the, of of what I actually thought. Now, in fact, my cube, who you see here, um, was understanding the, what I was trying to say even more deeply than I had done. Because what he was pointing out, and again this was an article on climate change, was that when we don't act on climate change, it's not because we're lacking some one key piece of factual information. So as soon as we would get that one bulletin on the BBC, we would leap out of the cave, right? That's not the right way to think about knowledge and climate change. Rather what Hume was arguing is that gaps in knowledge are more like thin ice. It's more like places of brittleness or weakness which require knowledge to be thickened. And so he also relied on another philosopher who argued that knowledge thickens and extends our understanding. So to get out of the cave, it's not enough to just drop in some more pieces of knowledge. What we need to do is actually to deepen understanding. That's the only way that we'll actually be motivated to turn around, to move out, and ultimately to act, to have our understanding of the ethics and the science go hand in hand. So this brings me actually to something that I haven't talked much about in these lectures, which is in fact rhetoric. I am as, uh, professor Linta mentioned the Gresham professor of rhetoric. And actually what I want to now argue is that rhetoric is part of the solution to this question of how we can help ourselves and others to leave the cave. When we use rhetoric correctly in scientific communication, it can help to reinforce and thicken our understanding. And so our trust, and this is especially important because of the emotional and social resistance that people often display to ideas and information that they think might threaten their basic values. So I wanna now draw on modern psychology and ancient Greek texts to show how serious this problem of resistance is and how rhetoric might help us. So let me start with what might seem like a trivial case. It's a game of American football. So the psychologist Dan Cahan has recalled a famous 1950s psychology experiment. And in his words, in this experiment, researchers showed students a film of an American football game in which officials made a series of controversial decisions against one side. So on one side you have one school, on the other side you have the other school. And one of the sides was the victim of bad refereeing. So when the students were asked to report what they'd seen in the tape of the game, the students who attended the offending teams college reported seeing half as many illegal plays as the students from the other institution. So in other words, their actual perception was deeply shaped by their allegiance, what they were invested in the side that they were on. And so Kahan draws from this immoral, which is very similar I think to Plato's Cave. He says, people find it disconcerting to believe that behavior that they find noble is nevertheless detrimental to society and behavior that they find base is beneficial to it, right? If there's a claim that would drive a wedge between them and their peers, they have a strong emotional predisposition to reject it. So people are motivated to clinging to whatever position reinforces the values and the group identity that they already share. And so they will resist efforts to give them information to help get them out of the cave. Because as Kahan says, if the truth carries implications that threaten people's cultural values, then this is going to make them more resistant when they hear new evidence, not less. So we have this problem that people may not listen to the science if they think it's threatening their values. And as American congressperson, Deborah Ross recently said, when people don't trust scientists, they don't trust the science. So there's a related problem here, which is lack of trust in scientists. And this also has been shown to be a real problem that stops people from truly coming to know and understand the realities of climate change. And this is a problem that other psychologists have called cold competence. So the problem of cold competence is when groups such as scientists are judged to be competent, but they're still distrusted in terms of their intentions. And so the psychologist Susan Fisk and Sidney Dupre have found that climate scientists in particular are often distrusted in this way. People will say, we recognize they know what they're talking about, they know the science, but we don't believe that they are well intentioned towards people like us. And Fisk and Dupre say that they will sometimes see people imputing motives to climate scientists, including as they write motives to lie with statistics, complicate a simple story, show superiority, gain research, money and so on. And so again, the issue here is whether experts are perceived as being well disposed to the listeners. And if they aren't, then people are going to spur the offer to lead them out of the cave rather than to accept it. So how do we solve this? How problem? Well, here I want to turn to another ancient Greek resource. And this is from Plato's star student, um, Aristotle. This is a much later, um, depiction of Aristotle because Aristotle wrote a work on rhetoric that can actually help us, I think address these deep issues in communication. So on Aristotle's analysis in his work called the rhetoric, there are three dimensions of rhetoric and we have to get them all aligned if people are going to be persuaded. So there is logos, this is the domain of logical argument, this is the substance, the knowledge, what you study if you're a scientist. But there's also ethos, this is character, your virtue, your general uprightness, whether you're trusted to do the right thing. And there's pathos. This is the domain of the emotions. So all three of these have to be working in the right way in tandem if a given act of communication is going to be successful. So Aristotle deploys this analysis actually to analyze exactly the kind of case of cold competence that I was just describing. So for example, he, he describes, there are cases when listeners will say that a speaker is knowledgeable. They'll say, we recognize that speaker has a command of logos. And they may even say that the speaker is general generally virtuous, that they have a good character or ethos, but they'll still distrust them. They'll still not want to listen to them. Why? Because they don't trust their emotions. They don't trust that the speaker has good emotional intent. In Greek, Aristotle used the word unia goodwill towards the listener and their own group. So Aristotle says, we often feel anger towards speakers who show hubris or contempt, right? Those are forms of pathos. We show anger towards them 'cause we think their emotions are contemptuous towards us. And he says, we often become angry at those announcing bad news. We might be inclined to shoot the messenger. So this resonates I think with problems that we see in climate change communication. Often people are perceived as talking down to lay audiences showing contempt for traditional world views. And again, I think this resonates with what Miles Allen was arguing in his most recent Gresham lecture on the environment when he addressed those that he called the climate establishment, saying that they have to work harder to avoid group think, to start thinking harder about who's being disenfranchised by an our technocratic expert led approach to climate policy. So in this, in this way, Aristotle's rhetoric would be a tool for what the political theorist Danielle Allen has called the Art of trust production. We have to use rhetoric in order to produce trust. And the only way to do that is to make sure that it engages emotion and character as well as simply argument. We, if we aren't attentive to the ways that communication might generate anger or envy or contempt, then we will fail to help persuade people to accept communication, to turn around and to see the way out of the cave. So this brings me to my third and final question for this lecture, which to remind you again was what if. So the question now is, okay, we do all our effort in climate change communication, we use rhetoric in the best possible way. But what if that falls short? In that case, can the telling of noble lies ever be justified? And on this point, actually Aristotle and Plato diverged. So here's a way of thinking about the problem of noble lie. So for Aristotle, the situation is always like this. In the long run, telling lies is going to not achieve the aims that you are seeking by telling the truth. So for Aristotle, these two signposts always point in opposite directions. But Plato in the republic does allow in some cases for the telling of what he calls noble lies so long as they express an underlying truth. So the idea here is that sometimes lies can be pointing in the same direction as the truth. And telling these lies is deceptive. It does in a way manipulate people, but it does it for a good cause, right? The end is supposed to justify the means. And so this brings us to a really deep question for science and politics and philosophy, right? Is lying ever justified in the service of some greater truth that the image of the cave would seem to portray? Well, we can draw here, um, on work, uh, by the American philosopher CIL Le Bach on the ethics of lying. And Bach was writing in the 1970s in the wake of the tragic debacle of American foreign policy in the Vietnam War, which had been led by purportedly the best and the brightest. So experts who lied in certain crucial moments of the war as was exposed, um, by the Pentagon Papers. And so the moral of her story resonates with the need for self-aware, skeptical testing of purported experts that I argued for also in my previous Gresham lecture. So box says We know how deception, even for the most unselfish motive, corrupts and spreads. And we've lived through the consequences of lies told for what were believed to be noble purposes. And I think many of us can think of other more recent examples in which that analysis also holds true. So the problem of noble lies is that it can fall prey to that tendency to group think, um, which I described, um, miles Allen as identifying and which people often fear even if it's not justified, as in the case of cold competence, right? We have to fear the tendency of elites actually to develop a self-righteous sense of moral and intellectual superiority. And so for these reasons, noble lies are not justified, I would argue in order to help people out of the cave. So to rule them out, we need an ethical code for science communication. And I've worked on this with some Princeton colleagues, um, a social scientist Bob Cohane and a natural scientist, um, on the right, Michael Oppenheimer and the three of us, um, worked on ethical norms for scientific communication. Now you can see here that we put honesty in a special category. I put it in green. But in our article, we put it in a special category because we argued that honesty is required of scientists in an unconditional way. It attaches to the professional role of being a scientist. But even if that rules out noble lies, the challenge that this list shows us is that we're back in the problem in a way of rhetoric because scientific communication has to be honest, but it also has to achieve audience relevance, right? It also has to persuade people from where they are. So we can set aside the problem of noble lies, but that just pushes us back into the problem of rhetoric as to how we can achieve rhetorically effective communication that people won't resist, but they will actually be motivated to accept. So we can set aside noble lies. But we still have the problem of aligning logos, ethos, and pathos. And so there are real trade-offs in doing this. These norms are all norms that scientists have to aim to satisfy, but they may have to figure out how to do it In any given case, trying to make scientific insights relative relevant to audiences who fear or resent what they take to be its implications are is never going to be easy trying to do so in the high stakes of climate change. The effort to get people to give up clinging to the certainties of the climate denial cave is the challenge of our lifetime. So the task is to experiment with ways to regain trust and renew faith in mutual goodwill. And we have to remember that trust once lost is very difficult to regain. And so my final image is this, um, and it illustrates a remark made by the sociologist Zainab to Epci, who recently reflected on the failures in public policy and scientific communication during the pandemic. And she said Trust is built in drops and lost in buckets, and this bucket is going to take a very long time to refill. Thank you very much for your attention.