 One of the central assumptions governing these Nobel conferences is that the questions of science which they discuss cannot be separated from questions of values. The connection between science and values has already been especially clear this year in the discussions which have arisen from the previous presentations. This afternoon's final speaker, Dr. Holmes Rolston III, University Distinguished Professor of Philosophy at Colorado State University, is superbly qualified to help us understand something about what the battle within means, both for our understanding and for our actions. His earliest academic training was in physics and mathematics, which he followed with degrees in theology and the philosophy of science. Some of the fruit of this study can be seen in his extensive publications, some of which you can read about in your conference program. Deserving special mention are three books, Science and Religion, a Critical Survey, Philosophy Gone Wild, and Environmental Ethics. Still more of the fruit of Professor Rolston's labor can be seen in the positions of trust and authority which he has filled. He has held editorial positions with respected journals, Environmental Ethics, and Zygon. He has been a consultant to Congress and a presidential commission. He has been president of the Rocky Mountain Great Plains region of the American Academy of Religion and president of the International Society for Environmental Ethics. His success as an interpreter of the meaning of scientific endeavors for our social and moral life can be seen in the impressive list of places encompassing five continents to which he has been invited. To name just a few, the Royal Institute of Philosophy in Wales, the Chinese Academy of Social Sciences, the United Nations Conference on Environment and Development in Brazil, the South African Forum at the University of Cape Town, and the Center for Theology and the Natural Sciences University of California at Berkeley. Next year he will address the World Congress of Philosophy in Moscow. In the last few days we have discovered that this philosopher, hiker, expert on mosses, wears all of this learning, all of this achievement with enormous goodwill, grace, and modesty. Please join me in thanking Professor Ralston for his contributions to this conference so far and welcoming him to this podium for his talk, Immunity in Natural History. Dr. Ralston. I do deeply appreciate being here in a way as a philosopher amongst all these world renowned immunologists. I worry that I might be a fish out of water. But in a way it's the duty of philosophers I think, try to think a bit more comprehensively perhaps about the work of specialists. And that is what I would like to try to do today. Philosophers examine world views, and the world view of an immunologist it seems at first is that life is a kind of a microscopic war in a microscopic world. And if you read the folder which drew you to this conference, you would read the following. Even in the relative peace and calm of a normal day, the human body is constantly under attack. Viruses, bacteria, and other trespassers launch regular assaults against the body's immune system, which raises an intricate web of defenses to identify and repel these biological invaders. That's the picture of the body as a kind of sabbathole that's under constant attack. There are innumerable hostile bacteria, viruses, and parasites. They lurk everywhere in the environment. There is a battle going on within. These enemies float in the air and infest the water and pollute our food, and they cover every surface we touch. Even the body's own cells can turn traitors, such as cancer cells. Now, that's a vivid kind of imagery, but imagery sometimes needs philosophical analysis, especially imagery that begins to color our world views. When we speak, for instance, of ant wars, or selfish genes, or even queen bees, we borrow words from one domain of experience and transfer them to another. So what about this battle within? Does that picture need to be set in a larger world view? What is the place of immunity in natural history? Now, if you see the world as a physician of infectious diseases, the world is just full of these nasty little things. Perhaps the imagery of battle, war is too strong, but surely we are engaged in a constant struggle for health. There can be no doubt, can there, that there's a struggle for health? That's not metaphor, that's straight truth. And, of course, these diseases can reach epidemic proportions. After the Second World War, the flu virus killed 20 million people, more than died in the war. And we forget how feared were the Black Death, or smallpox, or diphtheria, or cholera, before modern medicine won the battle against them. And I still remember in my childhood friends who died of polio and others who were crippled before Dr. Salk, who is with us now and with whom I felt like I was sitting beside a childhood hero when I spoke to him a minute ago. So we do have a kind of battle that we fight against these viruses and microbes. In fact, your body is at work, even as I speak, this very moment, killing these killers. If we had lived in the medieval world, we should have been on the constant lookout against demons. But now in the place of superstition, we have science. The microscope has given us the truth, which is worse than demons, germs, killer microbes, microdemons, billions of them in every nook and cranny. These microbes were, in fact, the causes of those great medieval plagues, which they took to be the work of demons. The first noble truth of Buddhism is that life is dukkha, suffering. And though the Buddha had no microscope, Indianology confirms him. Or the psalmist was right. Life is green pastures, but surrounded by the valley of death. It is a table prepared in the midst of our enemies. Microscopic enemies, too, adds the immunologists. So you can praise God for your natural killer cells. Still, this idea of a battle within might not be the whole truth, even from within immunology. Another word that immunologists often use is the word self. Maybe we better take a closer look at that word. Immunology is the science of self, non-self discrimination. So let's think about self-identity. Life involves organization, information, reproduction. Now, it's impossible for an organism to do these things unless it has an outside and an inside. Really, the essence of life includes the definition of self from long self, setting of limits to the self. There's got to be some kind of defining envelope. And after that, an organism can take in nutrients from the outside and sequester them for its own uses. The boundary line demarcates an order contained and maintained against entropy. An order which, in the prospect of death, has to be protected and reproduced. Now, an immediate implication of the fact that life has to have its boundaries is that you can have invaders. Things inside that don't belong inside, non-self inside, other cells violating these limits. And so life has got to control passage across a defining membrane. That's part of the bigger truth that life is constantly self-defense. There are all kinds of things out there that we must protect ourselves against. Cold, wet, dry, wet especially, we've learned these last two days. Solar radiation, poisons, predators. Cells have to be repaired when damaged. Outsiders that get in have to be put out. Also, there can be insiders that no longer belong inside. The body has to recycle dead cells or to program the death of cells that are no longer needed. Sometimes, insider cells get out of control and, lest these become tumors, they must be stopped. Immunologists can think of this as killing these outside invaders or these inside cells gone wrong. But we can also think of it as a kind of ordering the self. In the multicellular organism, such as a mammal residing in a biologically complex environment, this ordering of the self can become quite complex. In a world with millions of species, making billions of kinds of organic molecules, the body has to produce a defense against almost any kind of organic molecule except those of...