Start the Week

27/06/2011

Andrew Marr explores the limits of science and art in this week's Start the Week. The philosopher and neuroscientist Raymond Tallis mounts an all-out assault on those who see neuroscience and evolutionary theory as holding the key to understanding human consciousness and society. While fellow scientist Barbara Sahakian explores the ethical dilemmas which arise when new drugs developed to treat certain conditions are used to enhance performance in the general population. And the gerontologist Aubrey de Grey looks to the future when regenerative medicine prevents the process of aging. Producer: Katy Hickman.

Duration:: 42m
Broadcast on:: 27 Jun 2011
Audio Format:: other

This BBC podcast is supported by ads outside the UK. At Arizona State University, we're bringing world-class education from our globally acclaimed faculty to you. Ranked number one in innovation for 10 consecutive years and number two among public universities for employability. ASU isn't just ahead of the curve, it's creating new paths to success. Earn your degree from the nation's most innovative university. Online, that's a degree better. Explore more than 300 undergraduate graduate and certificate programs at asuonline.asu.edu. Thank you for downloading the Start the Week podcast from BBC Radio 4. For more information go to bbc.co.uk/radio4. Hello, well a small matter to discuss on this hot June Monday. What is it that makes us human? I'm joined by the neurosciences Barbara Sahakian to talk about changing our personalities and consciousness with drugs and electrodes and the ethics of that and by Aubrey de Grey who believes we can hugely increase human life spans. Indeed with new medical technologies, aging he says is not inevitable at all. But we're starting today with a refreshingly angry book of ideas, assaulting what its author Raymond Talis thinks is the besetting and dangerous folly of the age. The belief that we are humanity can be fully explained by our brains and evolved animal nature. What he calls neuromania and darwinitis. And here's just a flavour of what he says. To seek the fabric of contemporary humanity inside the brain is as mistaken as to try to detect the sound of a gust passing through a billion-leaved wood by applying a stethoscope to isolated seeds. Those who believe they can find our public spaces lit with explicitness in the private intracranial darkness of the organism overlook what it is that makes us human. Raymond Talis, this is a book which you say has been bubbling up inside you for half your adult lifetime at least. But it was provoked in particular. The final provocation was material written by John Gray, the philosopher, a very popular philosopher out there, who does believe that we are essentially our animal natures and that this has pessimistic conclusions for human natures. It just takes us through a little bit of what really got you riled if I can put it that way to write this book. In the background is is biologism. The notion that if you look at people clearly and look through them what you can see is underlying them is an organism that we are essentially, people are essentially organisms. And as you've mentioned in the introduction, there are two strands of that. One is neuromania, the idea that we are our brains because brain and mind are identical or the mind is the activity of the brain. And the other strand is that darwinism explains not only the organism homo sapiens, which it most certainly does, but it also explains what we are now. And that seems to me an idea that potentially if taken seriously has serious consequences. I mean, the most depressing thing is many people subscribe to these ideas without actually taking them seriously, without seeing through to their conclusions. But if you do look at the conclusions, you'll have to acknowledge, first of all, that we are animals. Secondly, that if we are our brains and our brains are material objects, as they most certainly are, we're simply wired into material world. So the notion of free will of ourselves as points of initiation of our actions goes out of the window. And I can see how if you subscribe to those things, you come to a nihilistic pessimism that is exemplified by John Gray's works, particularly in straw dogs. And you would argue that this reductionism, it all boils down to is the contemporary version of things like Marxists would say in the past. Everything can be explained by class struggle, or certain versions of religion would say everything can be explained by the fact that we are the playthings of God. We think we have free will and consciousness, but that is a that's a delusion. This is the modern version of that. It is and it's a more radical reductionism. And encouragingly, it's based on a more simple error. We do know that every aspect of human consciousness correlates with brain activity from the slightest sensation to the most exquisitely constructed sense of self. But correlation is not identity. And it's that simple error moving from correlation to identity that says because our awareness, because our behavior is accompanied by neural activity, our awareness and our behavior on your activities, because that simple error that people arrive at this profoundly reductive conclusion, which I think is much more reductive than Marxism, much more reductive than many of the other reductionisms that have been in currency in previous times. It's most extreme version. This is the reductionism which reports that a particular part of the brain is seen to light up under imaging when when makes a moral choice, for instance. So you found the center in the brain of moral choice, where you found the center of aesthetic enjoyment or whatever it might be. One of my favorite reductions is the reduction of love. Studies that compared brain activity when you looked at a picture of a friend compared with the brain activity when you looked at a picture of someone you were in love with, subtracted the one from the other, found the difference in activity and identified the place where that activity took place as the center for love. One would have to be a Martian not to acknowledge that love is a little bit more complicated than a response to a stimulus. And that in itself is a measure of the kind of thinking that's going on about complex psychosocial aspects of human life. The primary reductionism as it were leads to secondary reductions of manifestations of human life. There are two different things going on here. One is that Darwinist evolutionary biology is interesting to people because it appears to start to explain lots of things that we've noticed over many generations and have worried it will be interested in. Why do men and women often have different attitudes to foods? Now the Darwinist would say well you go back to the Pliostocino, the late Stone Age and men are out there foraging away and therefore they're interested in tasting foods that are on the edge of rotting more extreme foods and that's why today men like curry and women like etc. I mean taking a fairly simplistic example but one can see why people are interested in using evolutionary ideas to explain hitherto inexplicable aspects of modern life. But often those aspects on close inspection turn out to be untrue. I mean one of one of a comparable example one you've given is the idea why the girls like pink and boys like blue and it's because girls were the hunters and gatherers and they look for pink berries and so boys and boys were the hunters very well the girls were the gatherers who who pursued berries and member the hunters who liked conditions in which of the blue skies where you can see the beasts and so on and so forth. A little bit of history would you have told you that the reverse was true of Victorian times and in fact pink was often associated with with with a choice of color for men and blue being associated with the purity of the Virgin Mary for the choice of color for women. So you can see that the the data upon which these amazing reductive explanations are founded are themselves very dodgy. So what about neuroscience itself because there's no doubt that we are at a very very interesting and fascinating moment when we are beginning to watch the brain observe the brain in a way that we've never been able to do before and you know there are some fascinating conclusions about which bits of the brain are particularly active during different forms of thinking. It's been thrilling for me as someone has been a clinical neuroscientist of sorts over 20-30 years to see the new techniques for actually looking at activity in the awake human brain in a non-invasive way and it's delivered knowledge that seemed way beyond our reach 10, 15, 20 years ago. It's been particularly good at helping us to understand the impact of brain damage and in fact it's more useful I think when one's looking at the brain as a necessary condition of ordinary activity rather than seeing the brain as a sufficient explanation of consciousness. So you can see how brain damage influences what we can or cannot do in much greater detail but the metaphysical conclusions that have been drawn from this that's where I have a problem. So let's come on to the obvious heckle if I can put it that way which is if our humanity is not in the physical conditions of the brain where is it? Got to look at that question a bit carefully. If you're thinking that it's a question about where it is located in the physical world or is it floating in the air or something like that, so that clears the wrong sort of question. In the 50s the last century philosophers pointed out that certain questions were based on category errors and the sort of question like where is a thought, is it next to something else, physical and so on, the wrong sort of question it's like asking what is the nutritional value of prime number. So we're not looking for the human mind in another location, a physical location in the brain and if we think about it the brain has if you begin with the brain it's transcended itself. Brain science that enables brains to look at brains on the outside show how brains transcend themselves. That is to say they are already outside themselves but over hundreds of thousands of years brains as it were have got together and have produced something called the community of minds which you refer to in your original quote which is like the whispering of the leaves in a million petal forest which may have originated ultimately from the seeds, the acorns but no longer. So the answer to my question might well be in the culture. In the culture in the community minds in that which we have created together and which cannot be stuffed back into the inter-cranal darkness of an individual brain. Because a lot of people listening having heard the original proposition say ah yes, this is a religious attack on neuroscience but it's not. I'm not a tall religious, I'm an atheist humanist just like I'm not a dualist either. Some people think that I believe in the ghost of the machine but I think Cartesian dualism is just as bankrupt as materialism. And so the conclusion apart from stepping back a little bit from from sticking a neuro in front of everything, neuro, ascetics, neuro, literary criticism, neuro based et cetera, stepping back from that. What conclusions do you draw from from from the problem that you're discussing? Firstly there's a very interesting bit of work to be done to be rethinking the kind of creatures we are. I have set aside my own beliefs in a supernatural origin for human beings. I want to set aside a belief in a naturalistic account of human beings. There is now a very interesting bit of work to be done to try and understand the place of mind in the material world and our place in the world at large to try to understand what kinds of creatures, what kinds of things we are. Would that send you back to politics, economics, history? I'm sure it would. It certainly would resist the creation of neuro pre-fixed humanities such as neuro aesthetics, neuroeconomics and neuro politics and so on. Barbara, we're going to come on to neuro ethics in a moment. What do you make of the argument? Well, I think it's very interesting to raise this sort of debate because in the Oxford Handbook of Neuroethics, which I co-edited, Alan Leschner raises the fact that 56% of Americans agree that scientific research these days doesn't pay enough attention to the moral values of society. I think that there's been this kind of debate with the public sometimes which is unfortunate because sometimes neuroscientists when they convey their exciting results and clearly neurosciences are a very exciting area with a lot of important new developments. They sometimes don't give the same respect to the public perhaps in listening to what they have to say back. Could you go a bit further and say it can sometimes come across as a little bit glib and know-all? I'm a neuroscientist and I can tell you what you're like or what you're really thinking. Exactly. I think it does do that and I frequently say when I'm talking to younger neuroscientists, when you engage the public, you know, it's not that you're a scientist and there's society. You are a scientist in society. So this should be a respectful discussion and you should listen as well as give information. And yet, when Raymond says we are not our brains, you would say, "Oh yes, we are." Well, I have to say I disagree on that level because I think ultimately, you know, obviously not in the next five or ten years, but we will ultimately understand much more about cognition and emotion. But it doesn't stop us marveling at what the brain is and how, what an amazing organ it is and also the fact that there are many individual differences and that we, you know, our brains are changed by external, environmental, import and so forth. Does it undermine free will then? At this point in time, I don't think that does undermine free will. I mean, there are debates, actually, very interesting ones around substance abuse in that regard and some of them again are raised in the Oxford Handbook of Neuroethics as to if you're addicted, do you actually have free will if you're addicted to drugs? So there are some interesting discussions there, but mostly the authors, Stephen Hyman, who's very well known in the area of substance abuse and looked at this area, still says that ultimately these people, you know, they can make decisions, they can change their behavior and so forth. So all the moral questions still apply? The moral questions still apply. Albury to Gray, well, I mean, in some respects, you clearly see the human being as the soft machine, which can be retooled and worked on to extend its life much, much longer, but where do you stand on, on, on neuromania? Do you think there is, there is a neuromania problem? I'm not too sure that there's a neuromania problem. I'm generally with Ray on the question of what the relationship between the mind and the body actually is. I definitely think, I definitely have problems with materialism and we've got easy to do, so I think I'm probably on the same page as Ray, you know, on all of that. Where I'm a lot more hesitant is with regard to the dangers that Ray discusses in terms of the consequences of thinking in a reductionist way. And I guess I start from my own subjective, my own personal experience in the sense that I have gone through life pretty much undecided with regard to the existence of free will and the various other implications that Ray refers to. And that hasn't really had any effect on my values, I guess, on what I enjoy about life, what I think is important and such like. I think there may be other ways, and indeed more effective ways, to enhance people's moral compass than to focus on what I think a lot of people would consider to be a necessarily an abstruse philosophical point. Also, I think there may actually be dangers in going too far in the opposite direction, in the anti-materialist direction, so to speak. First thing that comes to mind is, to the extent that we regard ourselves as qualitatively distinct from other species, or indeed from humanity as we originally were, we may consider those other species to be of lesser significance, or we may play less attention to them and have less of a respect for animal rights and so on. That is an interesting point, isn't it? Because, I mean, people like the philosopher Peter Singer would point out that our cognition and our brains aren't so different from those of the other great apes, and that there is a danger of a sort of a kind of Supra-humanism, which does cut us off from the rest of nature and the rest of creation, and which certainly has its own dangers. I mean, you'd be interested in what the consequence is of that work. For example, I don't deny consciousness to animals, and I don't believe they cannot suffer. I'm very acutely aware of animal suffering, and I'm acutely aware of the human responsibility to limit animal suffering. So, the notion that we are remote from animals by a process of essentially cultural evolution over hundreds of thousands of years doesn't, in any way, diminish my responsibility to look after the cat and not to care for how animals are used in farming industry and so on. So, I don't think that necessary follows. All you've got to do is acknowledge the reality of animal suffering, and that's the end of it's reading. When you were talking about the fact that we've, as it were, leapt out of evolutionary advance, and through culture, we're able to advance much more quickly, and perhaps the origin of what we are is in the culture, rather than in individual dark, into cranial spaces with the brain. Is that any different, really, from what Richard Dawkins, who's often accused of being a reductionist, would describe as memes? I think memes are interesting. They're an attempt to rescue for Darwinism, human life, which is clearly not explained by Darwinian mechanisms. The meme is it's really a construct. I mean, an example of a meme would be such as, for example, tolerance for free speech. That's one the Donald and Ed gives, and I would like to say, is that meme unit of cultural transmission really analogous to a gene? Does something like tolerance for free speech, which is a noun phrase, have its own boundaries? Does it replicate? Does it seek, as someone like Richard would say, does it seek, as it were, to parasitize or infest human minds? It seems to me the meme is a rather desperate metaphor to try and bridge the gap between human life and animal life. Well, let's move on to some more concrete examples of brain science right now. Barbara Tackian, you've co-written the Oxford Handbook of Neuroethics, and certainly that's one where neuro is necessary is the prefix, because we are distinctly describing the moral consequences of some of the things that we are now able to do with the brain. Let me start with deep brain stimulation, which is a technique devised particularly for Parkinson's disease, I think, and this involves actually placing metal stems into the brain, doesn't it? Yes, that's right, and I think it's a very good example of what Raymond was just talking about, because obviously understanding how the brain works for brain damage people or for people with neuropsychiatric disorders makes it possible to have more effective treatments for them. So that's a very good example of where we've been able to use neuroscience for the benefit of society and health and mental health in particular. And so in deep brain stimulation, you go through stereotoxic surgery so that obviously you can very precisely implant an electrode permanently in the brain, and then a pacemaker-like device delivers an adjustable current, so you get this stimulation as you need it. And this is to do exactly what, to start with people with Parkinson's disease, frequently, obviously one of the common treatments would be L-dopa, or a drug which promotes dopaminergic function, which is a chemical in the brain associated with motor movement and other things as well. But sometimes the drug doesn't work so well for people, and they're resistant to the treatment, sometimes they get very negative side effects, sometimes they have to keep accelerating the dose, so this electrode can actually stimulate and restore some of the movement, get rid of the rigidity, reduce the trauma, and also it can sometimes then, even if they're on drugs, you can reduce the drugs that they're on. So that's a very straightforward clinical reason for sticking an electrode into a brain. Where is the ethical problem? Well, generally for Parkinson's disease, I mean it has been approved this device by the Food and Drug Administration in the USA, and I think it's reasonably well accepted that this is a very good treatment. It's put in the subthalamic nucleus mainly, although there are other sites that are used. The ethical issues come up because you could start using it at a younger age and then you may not know exactly what the long-term outcome is. These devices have to be changed from time to time. Could you use it simply to make yourself feel better? Well, that's the other thing. I mean sometimes if you don't get the current right, or if the placement is slightly wrong, you may get unwanted side effects, and also there's obviously with any kind of brain surgery, there's a number of dangers just associated with that. So there's issues like that, but I think the ethical issues become more apparent when you're moving into neuropsychiatric disorders, such as obsessive compulsive disorder and depression. So now they're beginning to use these stimulators for treatment-resistant depression. And again, this is a very interesting case where neuroscience has actually led the field because the mapping, so to speak, of the neurotransmitter systems and also of the neurocircuitary involved in control of emotions actually led this work, and they've found this subsenio-singulate as the area to place the stimulator for that. So another obvious area would be so-called cognitive enhancers, drugs that can be taken to make you concentrate for longer to deal with problems like attention deficit disorder and so on. And again, once the drugs are out there and available, lots of people will say well if I can take it, if it has these effects, why shouldn't I take it when I've got a very hard day's work ahead of me, or to keep me working for longer, or to get me through an exam, or indeed just every single day I go into work to make myself more efficient. Well that's absolutely right. I mean there is an increasing lifestyle use of these drugs, particularly Ritalin or methylphenidate, and Madaffinil is quite commonly accessed for that purpose. And is there anything wrong with that? I mean clearly there are all sorts of issues about ultimate side effects and so on, but that's the same with coffee, that's the same with alcohol, that's certainly the same with nicotine. Is there anything inherently different between popping a pill, biting a cigarette, pouring a drink? Well I've sometimes discussed with the ethicist and Manchester John Harris about the fact that, you know, some techniques are invasive, more invasive, I mean once you've taken a pill it's very difficult to counteract that, whereas if you have a system of coffee. So there are levels of invasiveness, but as you point out there's also the long-term safety and efficacy in healthy people which hasn't been determined yet. So that's the main problem, but people currently are accessing these drugs over the internet and that's very dangerous. So when you have a debate about the ethics of these pills or deep brain stimulation or whatever it is, how do you start to structure a genuine conversation between neuroscientists who have all the detailed technical knowledge that you display on the one hand and as it were the community on the other? In this country they tend to happen in the House of Lords very often, these kind of debates. Yes well I think the main thing is to be very clear about what the techniques can and can't do at this point in time and as you brought up some of the side effects that may be unwanted, so if you get overstimulated and some somebody becomes hyper aroused or disinhibited this could be very dangerous. So there's aspects to do with that and then to really find out what their views are, I mean how do they feel about it? Do they see it as different from coffee as you raise that issue? Treat the individuals and presumably their political representatives with respect above all, Raymond Thomas. Just a couple of points. One is that the use of deep brain stimulation for obsessive compulsive disorder. It seems to be in many ways what one is offering is a treatment at least it seems to be more rooted in neuroscience than the kind of treatments one has in the moment but of course another approach is talking to the person and I suspect both those things would work together so you can both use your neuroscientific knowledge and respect the person and that in many ways illustrates how complex we are, how we do have as it were a biological basis but also as it were a personal manifestation. The other point is about cognitive enhancers. It's easy we were always trying to enhance our cognition whether we're memorizing things, whether we're somebody sending their children to more expensive schools or whatever, so there's always a bit of competition in this respect and I think there's a certain mystique about some of the cognitive enhancers which perhaps they don't deserve given that so many other cognitive enhancers are actually much more effective and I wonder where that mystique has come from. Is it the idea that there is a pill that will utterly transform you that will be available only to a few so inequity comes and you'll have a new class war. Those have got the pills and those I haven't got the pills or anything. I think it's a very interesting point that you raise. I think part of it is the immediacy of being able to take a pill and then this society that we live in is looking for quick fixes so some of my favorite cognitive enhancers are actually education and exercise which work very well but people sometimes don't want to put the time in or they feel pressured and they just need something right now. I think also we've got a global economy and people are traveling everywhere all the time so jet lag becomes a big issue and then people are trying to recover very quickly from that because maybe they're only in one place for one day and have to perform well so I think that it's that kind of pressure and stress that brings on this sort of immediate reaction that we want to try these quick fixes rather than to do something that may be better in the long term. Aubrey de Grey, have you tried any cognitive enhancers apart from exercise, coffee and the old glass of wine? I personally feel that the difficulty with all of these questions when one really stands back from them is in determining where the actual ethics is. I find that when I consider any of these things in detail, insufficient detail to be able to form an actual opinion on whether such a thing is appropriate or not, I have to get down so far into the details of the benefits, the risks, the social implications of a certain amount of freedom of choice and so on that there's no ethics left. It's all sociology and psychology and medicine and I think that's a good thing. I think that if we avoid and if we encourage others to avoid oversimplifying these questions and trying to come to an abstract opinion on them without going into these details then we're going to be making progress. I think that we need to encourage people to understand that the devil is in the detail on all of these questions. I don't think it means there's no ethics left. What you mean there are no new ethical issues that emerge because obviously there's ethics implicit in all of those things, sociology and so on and so forth and I think that's what's very good about Barbara's book is it actually tries to identify those areas where there are genuine new ethical issues either on the basis of progress made so far or on the basis of progress that might be made in the future and I guess your whole aim was to anticipate ethical problems that may emerge rather than be as it were surprised by them when the technology comes. Absolutely. I think the authors were very good about stating some of the limitations of the techniques at the moment but anticipating what some of the problems may be in the future. And it comes back to a certain matter of modesty I suppose. I mean the world of neuromania is not known for its modesty but modesty is the key thing because you go back to those appalling operations back at the beginning of all of this where simply the frontal lobe was hacked out of people with various brain disorders through the eye socket That's correct yeah. So I think people are very careful now to you know separate out deep brain stimulation from these other old techniques that were used and they're very keen that it should be you know clear that you're evaluating the patient very carefully so are they suffering you know and they have their occupational social function and gone downhill are they risking suicide perhaps and then you have to worry about that as an issue have they had many other treatments including obviously psychological therapy before they start to think about deep brain stimulation or something of that nature. Well let's turn now to another area involving the brain and indeed the rest of the body which certainly has big ethical implications. Aubrey de Grey you've spent many many years now as a gerontologist studying aging and indeed campaigning to end aging which a lot of people would say is a complete impossibility and even a bad thing that are part of our essential humanity is the fact that we age and die but you're against this and you believe that the new techniques particularly at the tiny level of cells and mitochondria allow us to reverse or halt the aging process in our cells which is behind all the things that we visibly see as we age the lines and the grey hair and all the rest of it. Well first of all let me emphasize that I certainly don't think that we currently have the ability to um arrest or reverse. No sure it's amazing I think that um really all the content at the moment is that we may be within striking distance of such therapies um I think that subject of course as usual to adequate funding we're probably have a 50% chance of getting to what I would call a decisive level of comprehensiveness of treatment of aging within about 25 years but of course as with any new technology that's that far away the time frame is extremely speculative and I think that at least a 10% chance that we won't get there for 100 years. However yes I think that the advances that we've seen in the laboratory and the clinic over the past decade or two in regenerative medicine give cause for very substantial optimism. The original approach that people have been emphasizing for combating aging has been essentially to try to slow it down to if you like tweak our metabolism clean up our metabolism so that it lays down molecular and cellular damage at a slower rate than it naturally does and therefore postpone the the age at which that damage accumulates to a level that's pathogenic and causes us to become sick and eventually to die. And that approach has a number of attractions it seems like it's the sort of thing we might be able to do in consequence of our understanding of comparative gerontology of why some animals age so much faster than others for example. However when we look at the details it turns out to be extremely daunting largely because we are still extraordinarily ignorant about how cells and organs actually work and secondly because by definition if we're only slowing down the process of aging then both of us who have the misfortune to be around the table for example don't have so much to gain as kids would have. So my optimism comes from the exploration of a whole new approach which I already alluded to the use of regenerative medicine against aging which essentially involves not just slowing down the creation of these various types of molecular and cellular damage but actually repairing that damage periodically starting perhaps in middle age or even later so as to ward off the age at which that abundance of damage becomes pathogenic and yes I think that the advances that we've seen both in what we would conventionally call regenerative medicine such as stem cell therapies and also in areas which I tend to call molecular regenerative medicine things like the removal of molecular garbage inside or outside cells such as amyloid or oxidized cholesterol you know those things are going so well that I think we have genuine course for optimism. So we're familiar already with a society in which very very simple therapies and indeed changes in lifestyle mean that people are living much longer and not only that that there are people in their 70s and even in their 80s who are enjoying a lifestyle that would once be expected in your 50s and your 60s and the first part of what you're suggesting is that that will be extended into our hundreds and hundreds and twenties in due course sort of. So I think what we're seeing in contemporary society is that the health of old age is certainly occurring later than it used to but that seems to be a lifelong phenomenon in other words people are essentially spending their whole lives biologically younger than they would have been at the same chronological age possibly due to really early life phenomena such as better prenatal nutrition things like that. I personally feel somewhat pessimistic that that process will continue at the rate that we have seen in recent decades I think that we may be reaching diminishing returns in that area so I think that what we need is a whole new paradigm for the postponement of age later on. And that's when you turn to the molecular level. What about the obvious ethical question that a world in which people were living 250 or 200 years old would be a world in which it would be impossible to have that many more young people being born into it and that the whole traditional structure of youth optimism mating ideas and all these things we're familiar with the mathematicians have their best ideas when they're younger some of the greatest artists are at their best when they're younger and all of a sudden that we would have not only an aging population but a very fast aging and fossilized culture. I think all of the questions that come up in terms of concerns about problems that might be created as a result of defeating aging are important problems to look at and to discuss. However one thing that I always find I have to emphasize at the beginning of such discussions is that we not lose sight of the problem that we're resolving in other words the suffering that is associated with not being able to defeat aging that we have today. The fact is that in the world as a whole roughly two-thirds of all deaths are caused by aging. In other words they are caused by phenomena that don't affect young adults so much as they do people who are older in the industrialized world that proportion is something in the region of 90 percent. So aging is very clearly. I think the sense that's a good thing because it means they're not dying of accidents or wars. Certainly a success that's right it means that we have achieved a great deal and however it does mean that there's a great deal of suffering out there that we could eliminate and live that we could save if we were to be able to treat the ill health of old age properly and of course we spend a great deal of money trying to treat the diseases of old age one disease at a time or that the treatment of aging really constitutes is preventative geriatrics, preventative medicine for the ill health of old age and I don't think there are many ethical issues around the merits of preventative medicine in general. Reminalists do you think this is an assault on our humanity? I don't think it's an assault on humanity and I agree with Aubrey a lot. I agree with his aim. I agree with that there isn't an ethical problem and I don't think we will get a fossilized culture if we have an aging population. I think that's just the result of expectations of older people at the moment and their own internalizing other people's expectations. My main problem lies with the science. It seems to me I agree with you we can buy 30 to 40 years with current techniques and that'll give us time you think for us to develop molecular and cellular approaches to regenerative medicine. I don't think that's going to be the case for two reasons. One, theoretical reason and a practical reason, one is that we have very little idea how to bring about those changes at the cellular level. Even less do we have any idea how do we play out at the level of the organ or the organism and many of the mechanisms you suggest have the potential to increase rates of cancer to produce all sorts of unexpected effects. I speak as the veteran of millions of clinical trials where the whole causal chain has been set out clearly and the result has been disappointment and sometimes catastrophe and so that's the theoretical reason that the practical reason or based on evidence is that if you look at something like single gene disorders, great excitement 30 years ago how we're going to crack these with gene therapy, the excitement has really been greatly muted and I saw an article in the paper today about a publication in Nature about an animal model of hemophilia which may be useful for treating hemophilia which is a single gene disorder. So you can see how the evidence is very much against your timescale. 50/50 chance in 25 years we might have a 60 year old who's going to live to be a thousand. I don't think so. I think it goes right against what we might expect on the basis of the science. Right so I think that it is certainly quite legitimate to be nervous about the time frame predictions and to be more pessimistic than me in fact. I don't think that I would particularly argue with any of the challenges that Ray puts forward. I think that we all accept as scientists that there is a great deal of subjectivity in estimates of these thoughts. However of course the key point is that the sooner we start the single finish, the harder we try to develop treatments against aging the sooner we will actually achieve them. Whether it's bringing 100 years down to 99 or whether it's bringing 20 years down to 19 and if every single day that we are succeeding in hastening the defeat of aging saves 100,000 lives then I think it doesn't really matter which 100,000 lives. Barbara. Well I thought it was a very interesting idea. I mean I'm more concerned really at the moment with alleviating things like Alzheimer's disease which is something I work on myself so I'm very keen on cognitive biomarkers and other biomarkers for early detection of Alzheimer's disease so we can use some of these neuroprotective agents so that we can halt the disease process and have people have a better quality of life and well-being for those who are around now and I think we're closer to those goals than to yours and that would also obviously alleviate suffering as well as being a benefit to society so I'm more keen on that. I also just wanted to raise a question of motivation because one thing that does tend to motivate us is we know we have a certain number of years on this earth and so we we know if we want to do something and achieve something we better get on and do it so how do you feel about that? Well I certainly don't feel motivated personally by knowing that I've only got a certain number of years. It's never been a problem motivation for me and I think that's generally an educational thing. I think with regard to easier therapies I absolutely agree I think all easier therapies of these sort can act as bridges to the development of the more ambitious therapies and so I totally approve putting money in both areas. Well our conversation itself has aged withered and is finally putting itself to rest but has been entirely human all the way through so thank you to all my guests Raymond Talis's Aping Mankind, Neuromania, Darwinitis and the misrepresentation of humanity is out now so is the Oxford Handbook of Neuroethics co-edited by Barbara Sahakian and Aubrey de Grey is giving a talk at the Royal Institution in London on Thursday called Defeating Aging with Regenerative Medicine. Next week we've got China Mieville with his language obsessed aliens who have absolutely no concept of lying plus Ann Wilson and a poet Joe Shatcott talking about Dante's Inferno that great work but for now thank you for listening and