Episode 7- Alexander Broadbent- Philosophy of Epidemiology, Decolonising Medicine and the Pandemic



Sahana: Welcome to In Limbo Conversations! Today we have with us Alexander Broadbent. He is Professor of Philosophy and Director of Institute for the Future of Knowledge at University of Johannesburg. His central areas of interest include philosophy of epidemiology, philosophy of science and philosophy of law. Thank you Alex for joining me today for this In Limbo conversation!

To start with I would like to explore the way in which you define disease. Generally, we tend to look at disease as a lack of health. That seems to be the traditional idea of it. In some of your works, you have talked about the difference between disease and a mere lack of health. Could you please tell me a bit about it? How is disease generally looked at in philosophy of medicine or epidemiology? And how does your view differ from it?


Alex: Thank you. Yes, so my view is that diseases are more than a mere lack of health. And the reason for that is that there's no point having a concept of a disease separate from another disease, if you don't have that.

You can use disease, I should say, in two ways - one is just to mean lack of health but there's another sense in which we say somebody has a disease and it strikes me that the reason to do that, the point of doing that is that we want to say: it is a lack of health that is caused in a certain way. And that very simply is what I think disease is. It is a lack of health that is caused in a certain way. We can go a bit more into that perhaps but that's fundamentally what I think a disease is. So it's a very simple idea but it's a powerful one.

Historically, that is not how disease was thought about. Historically, certainly in the west and I don't know a great deal about traditional Indian medicine but I think to some extent there as well and certainly in Chinese medicine, there was much less of an emphasis on different diseases. Health was thought of as a balance within a person, and a lack of balance within a person was ill health, and in that concept there isn't really such a thing as a disease. There are simply imbalances that arise in different people for different reasons or different times. And that might be a contrast. The notion of having a disease that is separate allows, for example, the notion of vaccination and of treatments that might be the same for every disease, for every instance of the disease. So that's why it's a significant conceptual advance.


Sahana: Okay, so given that, how would you talk of coronavirus disease from these two different perspectives?


Alex: Well, Coronavirus disease is very much in the model that I've described, where we know what causes it. What I would say however - and this goes on to to the sort of distinction that's sometimes drawn between multifactorial and monocausal models of disease - is that there is a shortcoming in the way that diseases have become understood in Western biomedicine; which is that it's become all about one cause. So, in defining a disease with reference to a certain shared cause that all cases have, it has somehow become forgotten to some extent that there are actually other causal factors at play which have to be there in order for that disease to occur and that there may be further differences between people who are exposed to the cause that is the defining cause. So in the context of the Coronavirus, I mean, one of the things that's very clear in my mind, is that we don't understand very well why certain areas, and indeed certain people, but certainly certain areas and populations get it and others don't. It's very easy to say, for example "Oh Sweden did everything wrong, because look at Norway", but then if you compare Sweden with France or Belgium, that's no longer the case at all and why should that be? Or if you compare Malawi with South Africa, Malawi has very few cases. Indeed they did not do anything about it, they didn't lock down. South Africa did and it had a very large number of cases. So what can happen is that while we think we have a defining cause, we fail to understand that that actually doesn't complete the task of understanding the disease. One of the big things that I've emphasized in my work is that medical science, epidemiology stop with causation. They think that "Ah! We need to identify causes", and they stop short there because what they really need to do is explain. So it's not enough to cite a cause in order to explain.


Sahana: Okay, okay. So, I think this smoothly takes us into the models that you already mentioned. So, for our audience .. Alex has done a ton of work in philosophy of epidemiology. In 2013 he brought out one of the first philosophical works on it, titled "Philosophy of Epidemiology". And this book also talks about the nature and role of explanation and prediction in epidemiological analysis. This includes aspects of the process, like inductive reasoning, causation and prediction. So in that text, and many others like that, you just mentioned you have talked about multifactorial ways of approaching a disease and also the old-school monocausal way of talking about it. So, could you briefly tell us about these two different ways?


Alex: Yeah. So going back to the 19th century, in the European tradition what happened was there was a shift in the way of thinking about disease that came about with the idea that diseases were caused by germs, by agents that would invade a body and give rise to basically the same symptoms. Prior to that, as I mentioned, that wasn't really how diseases were thought about. In the Hippocratic model, it was about balances of fluids. Of course it was understood that certain things caused problems and one of the great criticisms at the time that the German theorists made of existing medicine was, if you look in medical books, what you see is just a long list of causes and long lists of possible effects and there's lots of overlap. You know, being cold, poor nutrition, liquor and so forth. All can lead to anxiety or to flu or to cholera and so forth. And the argument was - this is not very scientific. Basically the argument was - look, we've just discovered these things that you can see with these microscopes which is kind of a new thing .. which are present only in people with cholera; and for example the Vibrio cholerae is only present in people with cholera. So we can explain cholera not by reference to all these different things and certainly not by reference to a sort of bad air blowing across the town, which is what they thought before, but by whether people have this or not. And then to prevent it we simply prevent that getting into them. So what happened then of course is that you get sort of modern biomedicine and the idea of antibiotics and so forth, and that was very successful for certain diseases infectious diseases, particularly bacteria. Though, what happened in the mid 20th century, were two things - one is that this early success with, particularly, antibiotics was not replicated for viruses. Modern medicine can't .. still can't do very much about viruses, it just can't. And the Coronavirus is a very good example of that. I think people don't understand just how impotent medicine modern medicine is in the face of viruses. Really very little can be done. The reason that things like antiretroviral treatment of HIV are celebrated is precisely because there's so little that can be done in general. The other thing that happened was there was a shift in the burden of disease, in developed countries, towards chronic diseases and things like cancers in particular. And cancers , heart disease and those sorts of things.. they don't have single causes. They don't fit that monocausal model. You can't define cancer in terms of what caused it; even lung cancer, which is very largely defined. Almost all lung cancer is caused by smoking, but it makes no sense really to call that “smoking disease” because smoking causes lots of other diseases.. and because not all lung cancer is actually caused by smoking. There are some that are not caused by smoking - very, very little but there is. And so people started to explore multifactorial conceptions of disease for purposes of epidemiology and that was to identify the various risk factors to which a population is exposed that might be causally linked to the disease in question. The trouble with that of course, is that in a sense it's going backwards, because once again you get what I call the catalog ejection. You start producing these long catalogues of causes; and yes they are causes, but that's not really much of an advance in terms of a scientific advance, in terms of achieving a general explanation. So, back in the 19th century, Jacob Henley said in medicine books you see long lists of causes and the same effects. It's like physicists teaching that objects fall because there are openings and boards break and ropes break and so forth. And that's true that those things cause objects to fall, but that's not physics. And in the same way that's the criticism you can level at the multifactorial model of disease. You can say, well yes it's true that say depression, you know there are all these risk factors for depression, a large number of them and yes we can establish that many of them are causal. But that's not clear that we've understood depression better in doing so. So that's the criticism that I make of that model. And then I try to combine the benefits of those two with my own with my own view.


Sahana: Okay. So, since you just got into that. So you had also introduced and suggested what you just said, the contrastive model. So with this new model of disease .. For the audience, Alex has tried to preserve the benefits of the monocausal model without the overarching commitment to classifying the disease in terms of just one cause, if we can say that I guess. Could you please tell us a bit about the contrastive model? And how does that work?


Alex: Yeah, so the idea is that you need to explain. A cause needs not only to be a cause but to be a causal difference between people with the disease and without it. So, it's not enough to establish that something is a cause. You need to say, what difference does this explain? So you need to identify something that is .. for example, it's not enough to say A lot of people who are obese also have obese parents and that seems to be causal in some way. You've got to go further and say well that is causal, but what it ... what's the contrast class? Who are the people who are not obese? That.. perhaps would have been obese, had they had obese parents. That's another way to put it. And this is somewhat in line I think with a development in the epidemiological, methodological literature which is called the Potential Outcomes approach, which is a technical attempt, really to enforce this kind of reasoning on estimates of effective science.


Sahana: Okay, so if I remember correctly, in one of the papers you had mentioned that the contrastive model could handle the asymptomatic cases which have been generally excluded in the traditional and previous accounts of disease. So if that is the case, and if you feel up to it, could you tell us how the contrastive model could explain the asymptomatic cases of Coronavirus better than other accounts?


Alex: Yes, that's a good example. I mean what you do is that you look for, again, you look for the differences so it's a very obvious idea. But you don't settle with saying okay we understand this disease. You look for differences between the people who are asymptomatic and who aren’t. So you effectively subdivide the disease into further subdivided diseases. I mean another example was this woman Typhoid Mary - she was known as .. who was infected with typhoid but she suffered no symptoms, which is something that happens. People often do suffer no symptoms. Well, not often but it does happen and you know it doesn't really make sense to say she has these symptoms that were caused by this cause because she doesn't have the symptoms. So what you have to do is do a further contrast class where you say people with the cause but without these symptoms, there's a further difference that marks them off from the people with the cause and with these symptoms and you've got to go, then go look for that difference. So it's not you know it's not rocket science. The point is that it's, as I say, these conceptual.. I mean you know It's philosophy it's not rocket science! The conceptual factors actually make a surprising difference in the way that people approach these things. So, if you look, for example, at the focus on vaccination. You know the idea is there. The conceptual framework is - Well there is a cause for this disease and we're looking for something that intervenes on that cause. If the conceptual framework were, look there's a causal difference between certain people with these symptoms and certain people that don't, and that causal difference however is not a causal difference between everybody who has the infection. So to understand it better, we need to identify those differences. I hope I'm doing a fair job of explaining it, but it's a conceptual move that changes the way one looks at things and in the context of social epidemiology. Which is where people have really pushed the multifactorial model. The reason for this is that there are in fact causes of disease that are not the defining cause. So, there is a reason, for example, which is that certain people live in very, very poor sanitation conditions. That is a cause. But if you focus exclusively on the bacteria then the effect is that people neglect that and living conditions aren't improved. Cholera is understood by medical science and yet it's not prevented. If we weren't thinking about it as a disease caused by this bacteria, but we were thinking about it as a disease caused by living in a situation with poor sanitation then perhaps we would do more about it. Interestingly, that is actually one of the main reasons that the people who opposed the monocausal model back in the 19th century opposed it. The hygienists - they worried that if you identify diseases with germs, it would basically let the authorities off the hook for improving living conditions in the slums. So there's quite a lot of historical resonance. In the Coronavirus case of course, it's the other way around. The people who are largely more resistant to the disease are in fact generally poorer because of the fact that youth is so strongly correlated with poverty. So in fact, it's somewhat the other way around. And there I think the real missed opportunity was seeing that you don't need to do the same sorts of things in, say Africa, as you do in, say Europe, because the ages are so different and there it's really worked against this monocausal way of looking at things. It has really worked against the local population.


Sahana: So that's really a new way of looking at diseases. I haven't really thought about that. So, this sort of finishes the first segment which was about epidemiology. I was hoping that we could talk a little bit about Medical Cosmopolitanism. So, in his book "Philosophy of Medicine" Alex proposes Medical Cosmopolitanism, which is broadly based on (Kwame Anthony) Appiah's ethical framework. Click here to know more about Appiah's framework. So, Alex could you share a bit about medical cosmopolitanism and how such a framework could help us to navigate the current situation?


Alex: Yeah, so Kwame Anthony Appiah wrote a book about cultural disagreement and ethical disagreements between cultures. And it's a very interesting book called "Cosmopolitanism". I try to break down, I try to further analyze it into several components. One of these is a metaphysical component, which is, broadly speaking, a realist component. Which is where you say, look there there are actually facts of the matter out there about certain things. And when I think we talk about medicine, to me, it is very unattractive to say that medicine and health are relative to cultures. For example, there was a phrase that sometimes goes around "African solutions for African problems." I don't like that, because I think that problems like health are basically pretty universa. And whether a medicine works is pretty universal. I think it's wrong to say "African medicine for African people.. .. European medicine for European people." In fact, when you say it like that, it has a nasty flavor to it. I think that whether something works is a fact. I think that, broadly speaking, illness is a universal human experience. If you have a sick child in your arms, you don't care what culture the cure comes from, you just want it cured. So that's the metaphysical component, which is the realist component. But there's also an epistemic component. The epistemic component is one of humility, and it acknowledges that basically humanity as a whole, over its history and in all these different cultures has been really bad at medicine, really bad at curing people. There are still very few cures and there are still very many conditions for which there's no effective cure. There are things for which we now have cures, that we didn't used to, but there are many things we don't. I mean, for example, I suffer from lower back pain. Nobody really knows what to do about low back pain. There are lots of ideas out there basically that, basically we can't do anything about it. There are lots of people who suffer from it. There's no clear evidence that one thing works, despite our supposedly advanced medicine. So I think it's very wrong for people to be very, very confident about any particular medical tradition and I think it's wrong even to be too confident about treatments where there is very good evidence. However, I do think you can say certain things don't work and you can say certain things do work. You just have to be humble in the way you get there. And the point of that is that there are people who are really vitriolic about whole medical traditions, whole approaches and write them off. And I think that's inappropriate because nobody is in a good position to do that. No medical tradition has been very successful. So the combination of those two things means one should believe something works, but be cautious particularly about criticizing other people for it. There's also a notion of the Primacy of Practice, that I like very much in Appiah's work. And for me that's a pragmatic component. The Primacy of Practice said basically, look we agree much more readily about particular problems and how to solve them than we do about principles. If we try to agree, you know, two people try to agree on whether there is a god and what character that god has and what the god commands, they'll be talking forever. If they try to agree whether or not it is wrong or right to help a certain poor child, for example, they'll probably agree in many, many, many more cases than they would about whether there is a god, what kind of god, and so forth. And I think the same is true in medical contexts. So rather than saying, I do not believe in osteopathy. You rather say - "Does this work?" and you start there. So in that respect, it has something in common with the evidence-based medicine tradition. There are other things that I don't think you can be so strict about the nature of evidence, as they do, at all. And I think that follows from the epistemic humility. I think you can, for example, admit anecdotal evidence. And I don't think the evidence-based medicine people are epistemically humble at all. But in this respect, I am on the same page - you look at what works on an almost case-by-case basis. You don't just write things off in advance. So those things together create a framework which I call cosmopolitanism. Which is, I think in contrast to a kind of strong medical realism or a strong medical relativism, where the realism says - Look this is what works and we know it and it's backed up by theory and our theories are true. And relativism says, You know, well you know, of course the disease in the West is different from a disease in the East and all these different traditions, the different ways of getting at the same thing. That is for me not attractive about medicine. You know, when it comes to it, disease is such an immediate and universal human experience. We know from empirical studies that when people are sick they just go to whatever works. They don't care what tradition or whatever. So I think it's very much more in tune with the way we normally approach disease as well.


Sahana: So, on a related note I'm reminded of.. you also explored a very interesting and usually less looked dimension of decolonizing medicine towards the end of this book, "Philosophy of Medicine". I guess there was a chapter on this. Could you tell us a bit more about how power relations feature in, say, the current response to Coronavirus from different countries or any other aspect of the situation which interests you, which could depict this?


Alex: Decolonizing medicine. The idea there is specifically to apply the cosmopolitan model to the questions that are quite current at the moment, about epistemic decolonisation. That notion is a tricky one when you apply it to things like medicine. Because the implication is, you know, we should just kind of back-off from the idea that certain things need to be universally provided. We should provide support also for all kinds of other traditions, invest in them at a state level, and so forth and when resources are scarce, that's actually quite a big thing and it could cost people their lives. If the things don't work at the same time, if you're epistemically humble, you do need to acknowledge that there might be some overlooked cures that are not part of the mainstream tradition. What I basically try to argue there is that one can't.. if you can make sense of the notion of decolonising medicine, it can't be either simply giving a load of medical resources to everybody. Which is how it is often thought of in the western context, where there's no sensitivity to the fact that medicine is culturally imbued and that different people have different medical beliefs and they are deeply held. You can't just say: "Right! We're going to put in vaccination clinics everywhere." and not ask anybody about it because it might not work because people have their own views about what causes disease and this is something that gets encountered quite commonly. Well-meaning western institutions will put in a whole load of medical facilities and they're just not used and then somebody thinks to look at the social context, the cultural context. And they realise that there's a reason, there's some beliefs and so forth that are quite different. Some perspectives that are quite different. That means that people aren't utilising those facilities. So that's a sort of well-meaning way to try and decolonise health care. But nor can you say, well we're just going to approach this like it's poetry and say Look, you know the judgement that Shakespeare is better than..I don't know..pick a poet from another culture. You might say..Look, that's just entirely a matter of taste! - you might say that but I think that even if you say that, you certainly can't say: "Well, whether vaccination works is really a matter of perspective." I don't think you can say that and that's because whether you get the smallpox or whatever it might be, it is not a matter of perspective and it's just not respectful, really, to the way that ordinary people actually think which is just not nearly so precious about theoretical frameworks. So what you have to do is steer a middle ground in some way. You need to take both factors into account. You need to insist that there is something. There is some fact about whether something works or is appropriate but you need to be humble in your approach to getting at it. The combination of those two attitudes.. I mean when you say it, it kind of sounds simple..but it's that combination of attitudes, just is quite uncommon in the way that health is approached.


Sahana: So, following from what you just said like this is also related to the article "Why ‘one-size-fits-all’ could have lethal consequences", I think you had written with Benjamin Smart. So in that, the advice of WHO or other international organisations is global while the context is local. So how do you think - you also have worked a bit on philosophy of law from what I remember - so, how do you think countries, from their side, if they are developing ethical frameworks could sort of reclaim their context? Like, what would be the concrete measures that you think..? Like I do remember the seven relevant considerations were given in the Daily Nous article, but as governments, do you feel..certain measures can be mentioned in the ethical frameworks that ethicists create for a country?


Alex: In different places, yeah. I think that there has to always be an understanding that local differences matter and that's not just an ideological thing, because in almost all cases, they do. This has been shown in a number of instances. To me, it's obvious in the Covid-19 case because the same thing, broadly speaking, was attempted worldwide. The consequences have been very different and will be very bad in some cases, much milder in others. The disease itself has likewise had very different effects in different places. You can also see it with, for example, HIV prevention. You can't use the same measures in San Francisco as you do in rural KwaZulu-Natal in South Africa. There was actually a study done on this, where there was an attempt to identify measures that would work and - actually the people who did it end up winning a Nobel Prize - and one of the things they emphasise is that you have to take the cultural context into account, particularly around coupling patterns. If you have a situation where infection rates peak among men at the age of 25 and women at the age of 15, then that tells you something about the power relations between the couple. If you have migrant workers where the men are coming home once a month so the women know when they're going to be engaging in sexual intercourse, then again giving them a pill that they have to take every day is not going to work so. This perhaps goes a little bit back to this monocausal versus multifactorial idea as well..in that, even when you've found something that works, in the sense, that it does break the transmission chain as it were, it might not work in the field. In the sense that, when you put it out there, the field differs in different contexts. This is point has been made by a number of other philosophers as well but in the context of coronavirus is certainly quite dramatic. And it's remarkable, that it's sort of been.. it just seems like it was just ignored, and still to some extent is being ignored.There's very little sensitivity. I saw that yesterday, or a couple of days ago, 24th I think.. There was an article that the BBC put out covering a story in science about some researchers trying to understand why a lot of Africans appear to have had coronavirus but just doesn't seem to have taken much toll and they're saying.."Well maybe, it's because Africans on average are younger

We knew that in advance. I mean we knew that half of the population of Africa is 19 or under it..a median age of 19. It's obviously going to have a different effect there than in Europe where the median age is 40. When it comes to a disease where we think we know the cause, seems to just go into the back of our minds. So yeah, I think the framework just has to be..as we said there.. you can't have this approach that one size fits all and it is very much the ethos of modern medicine. That one size..that's the goal..is to get something that one size fits all and the assumption is that we have that and in some cases, perhaps we do but in many cases we don't.


Sahana: Okay, so that brings to the end the second segment, which was about philosophy of medicine and decolonising medicine. So this is the last segment and it's about how philosophers can contribute to the public domain. So, in your blog Philosepi, you have talked about the role of philosophers of epidemiology during the current pandemic situation. So could you tell me a few ways in which philosophers of medicine and epidemiology could engage in the current situation to contribute?


Alex: Yes. I think one thing that philosophers need to do more is they need to be more willing to challenge the way people are thinking. A history of philosophy is full of that and philosophers like to think that they do that because they ask questions like Do we really exist? Is there a world out there? and all this kind of thing. The trouble is that those kinds of

challenges aren't really particularly challenging because everybody knows that. It's done in an academic context and we're still going to have our lunch afterwards. Where it's really important for people who are trained in thinking carefully and reasoning to start challenging is actually when there is a big public crisis. And that's because in a big public crisis, it's very common for people to panic and some protection might be provided and offered by people who are trained to think about things carefully. I think there's a problem, which doesn't happen as much as it might. It does..I mean..I think many philosophers have contributed very helpfully but I think one needs to push oneself forward a bit and as philosophers we’re trained to be very cautious and very careful and in the medical field, there are a lot of very loud voices who are frankly not always that careful, have a very strong view and that's quite intimidating. I think that one of the things that philosophers need to do is perhaps just be a bit more confident about sharing doubts and reasonings. One of the difficulties of doing that is that one of the messages that philosophy often conveys is that “it's a lot more complicated than you thought”. That is not an easy message to convey. It's not a message anybody wants to hear. And it's very very hard to go on TV and just say - "Well you know.. it's not really..it's not simple as that." especially if you're talking against somebody who really, really has a very strong view and is very convinced. So I think part of what philosophers can contribute is just that kind of appreciation that things might be a bit more complicated and that simple answers might not work and they can contribute perspectives that might have been forgotten. They might identify problems that have been overlooked. Many philosophers have done some very good work on this during the pandemic. I think that it's perhaps something we need to train our students to do more as well - engage in public debate like this. As I say, it is not something that modern philosophy trains us to do. We are trained to talk to other philosophers and I think this pandemic in particular has shown that there is a huge amount philosophy can offer the wider world. Especially when we're facing difficult problems and people start to realise that actually, the solution might not be simple.


Sahana: Thank you! Thank you for that! So in the end, I thought I could just end with the call to arms that you had written on the same blog, so here goes for our audience:


"A call to arms. The skill of philosophers and the value in philosophy does not lie in our knowledge of debates that we have had with each other; it lies in our ability to think fruitfully about the unfamiliar, the disturbing, the challenging and even the abhorrent.. the coronavirus pandemic is all of these things, let's get stuck in!"


Thank you Alex for joining me on this conversation today! Thank you so much!


Alex: Thank you very much! It's been really fun. Thank you so much!



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