Question: 1. From The Following List, Explain The Difference Between Two Of The Following:Boorse’s Naturalistic/objective Theory (See Kovacs Or Lecture Disease Part 1)Nordenfelt’s Normativist/holistic Theory (See Kovacs Or Lecture Disease Part 1)Kovacs’ View (See Kovacs)Social Constructivism About Disease (See Disease Part 2)Disease Eliminativism (See Disease …

The concept of health and disease

Semmelweis University of Medicine, Institute of BehaviouralSciences, Department of Bioethics, Budapest POB 370 H-1445Hungary

Abstract. Examining the naturalist and normativist concepts ofhealth and disease this article starts with analysing the view ofC. Boorse. It rejects Boorse’s account of health as species-typicalfunctioning, giving a critique of his view based on evolutionarytheory of contemporary biology. Then it gives a short overview ofthe normativist theories of health, which can be objectivist andsubjectivist theories. Rejecting the objectivist theories asphilosophically untenable, it turns to the subjectivist theories ofGert and Culver, and to the view of Nordenfelt. These theories givequite a good subjectivist account of health and disease, but theydo not pay enough attention to the notion of the environment,without which it is impossible to define health and disease.Starting with their definitions but introducing the notion of“reasonable social norms”, the article arrives at the followingdefinition of health: The healthier a physical or mentalcharacteristic, process, reaction is, the more it makes it possiblefor the individual to adapt to reasonable social norms without painand suffering, and the longer, and happier a life it will be ableto ensure him in that society.

Key words: disease, evolution, health, humanenvironment

There are two main lines in the literature on defining theconcepts of health and disease. The naturalists believe that theseare basically value-free and empirically dis- coverable notions. Bycontrast, the normativists argue that health and disease areessentially evaluative notions, which are not discoverable but onlyadvocable.

The most influential proponent of the naturalist view is C.Boorse, who argues, that disease is “the inability to perform alltypical physiological functions with at least typical efficiency”,1and health is simply the freedom from disease. According to Boorsethe functions of an organ are “ its species typical causalcontributions to the organ- ism’s survival and reproduction”.2Health is normal func- tioning, where normal means the speciesdesign while diseases mean an interference with the functions inthe species design. Thus, we could determine health in the same wayas we determine whether a car is in a good mechanical condition. Acar is in a good condition, when it is very similar to its design,when all its parts conform to the detailed specifications of itsdesigner, regardless, whether the original design was good or not.Similarly, an organism is healthy when its organs function accord-ing to their design, “made” by evolution. A person who

This article is based on the paper, presented on the VIthEuropean Conference on Philosophy of Medicine and Health Care,Budapest, Hungary. August 12–14, 1992.

would acquire by mutation a sixth sense, or the ability toregenerate severed limbs, would not be healthier than we are,because sixth senses and limb regeneration are not part of thehuman design.3 Similarly, “health requires a person to manufactureinsulin but not vitamin C, since our species does make one and notthe other. Controlled dia- betes remains a disease; to controlscurvy is to eliminate it”.4 Thus health is conformity to thespecies design and not the conformity of this design to ourvalues.

But how can we know, what the design of the species was? HereBoorse is not very clear. He thinks, that we can deduce the designof the species from the statistical distrib- ution of its variouscharacteristics. What statistically is the most frequent ortypical, is probably the species design. This, however, isevidently false. There are a number of counterexamples. Caries, arelatively high blood-level of lead in people who are living inmodern cities, the typical increase of blood-pressure with age,etc. are very frequent today, though they are surely not normal, astheir cause is the way of life and environment in which themajority of the people live in a modern society. Therefore Boorsethinks that when too many members of a species seem to be diseased,then the cause of the disease can be called external. In such caseswe can say that the environment is atypical, so the environment canbe called abnormal, while the species remained healthy, and thepathological signs, which can be found at most members of thespecies, can be called normal reactions to the effects of thepatho- logical environment. So we can slightly modify Boorse’sthesis, and – in accordance with his line of reasoning – say

Medicine, Health Care and Philosophy 1: 31–39, 1998. c 1998Kluwer Academic Publishers. Printed in the Netherlands.

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that those functions are normal and healthy which would be themost frequent in a normal (i.e. typical) environment of thespecies.

Boorse’s theory implies that the more an individual approachesthis species design, the healthier he is.

From an evolutionary point of view Boorse’s claim is neithertheoretically nor practically true, as evolutionary the environmentis always changing, and the species must adapt to these changes aswell. And those individuals survive, and can spread their genes,whose adaptation to their environment is better than others and notthose, who are typical for the species. The logic of evolution is:the better adaptation a somatic or mental characteristic ensures toits bearer, the healthier it is, regardless whether it is typicalor not.

Let us see some examples. Dubos cites many exam- ples from theoften observed fact, that when a previously unmet virus orbacterium is introduced into a population, 2/3 or 9/10 of thepopulation can die from the resulting epidemic, because theindividuals were not adapted to the infectious agent. This happenedwith the American Indians, after Columbus discovered the newcontinent, and with the Polynesian population. After the time ofCook’s first visit in 82 years the population of native Hawaiianshad fallen from 300000 to less than 37000. There are many similarexamples from human history, and much empirical evidence from thesame phenomenon in wild animal populations.5 In these cases itwould be absurd to say, that those atypical characteristics, whichmade it possible for some Hawaiians to survive, were not healthier,than those typical characteristics of the majority of theHawaiians, which caused their death in the new infection. Acontemporary example is AIDS. The pre- viously mentioned patternrepeats itself: the HIV virus has only recently been introducedinto the human popu- lation, to which humans are not adapted, so itis highly lethal. There are however some – today highly species-atypical – individuals who happen to be somehow resis- tant to theHIV virus. Can we say, that they are diseased because they arespecies-atypical? If the HIV epidemic continues, there will surelybe some kind of adaptation to the virus after some generations,even if no cure will be found, and then the lethality of AIDSinfection will spontaneously decrease. This adaptation can takeplace by natural selection. The genes of those who are resistant tothe HIV virus are presently highly species-atypical. However, thesegenes will spread more. Thus the charac- teristic of HIV resistancewill be spread, and this – today highly atypical – trait willbecome the typical one, after many generations. This is the basicprinciple of evolution. What is species-atypical today, can beadvantageous in a

new environment, and will become species-typical in thefuture. Evolution itself is nothing, but successive devi- ations ofindividual organisms from the species design, which – in some cases– produces more adapted organ- isms, and thus can mean the firststep in the development of a new species. Evolution is a constant“experiment” to deviate from the species design, and the sheerexistence of extinct species attests to it, that the species designdoes not always mean health, but it can represent – by the dramaticchanges of the environment – disease and death.

Thus to be species-typical, to be close to the species design,shows only how healthy the given organism would have been in theprevious environment, to but tells us less about how healthy it isright now, in the currently existing environment. This phenomenonis called “time lag” in evolutionary biology. Most animals are“probably out of date, built under the influence of genes that wereselected in some earlier era when conditions weredifferent”.6

As Dawkins put it:

“Moths fly into candle flames, and this does nothing to helptheir inclusive fitness. In the world before candles were invented,small sources of bright light in dark- ness would either have beencelestial bodies at optical infinity, or they might have escapeholes from caves or other enclosed spaces. The latter caseimmediately suggests a survival value for approaching lightsources. The former case also suggests one, but in a more indi-rect sense. ”7

Thus the species typical behaviour of some insects ofnavigating in the darkness of the night with the help of the lightof the stars was adaptive when there were no artificial sources oflight at night, but today it causes them to die. This means that aspecies-typical, adaptive behaviour in environment A can becomemaladaptive in environment B.

Boorse’s view of health and disease is based on a Cartesiannotion of organisms as machines. This view conceives diseasedorganisms as defective machines, and as we saw, a machine isdefective when it differs from its original design. Thismechanistic view does not take into account that living organismsand their environments must be seen as a whole, and that the healthor disease of any organism cannot be determined without referenceto adaptation to the environment. Boorse’s description has to bereplaced by an evolutionary account of health and disease, which isbased on the view, that organisms have to adapt to changingenvironments, and that they have to compete with each other forsurvival during this process. Thus there is no strict “design” ofthe species, but indi- vidual organisms represent continuous“experimentation” to deviate from the loose “design” in order to“assess”, whether they will be more successful in adaptation thantheir predecessors.

“Species design” from an evolutionary perspective

From the point of view of health and disease the real questionin many cases is not what exactly the design of the species is, butrather: whose interest is served by that loose design. The interestof the species? The inter- est of the individual? The interest ofindividual genes? According to Dawkins there are arms races betweenand within species. There is strong competition among them: theadaptation of one species to its environment (e.g. the adaptationof lions to catch zebras) results in counter- adaptation from another species (e.g. zebras can increase their ability to escapelions). During this process species and individual organisms canmanipulate each other so that the behaviour of one entire speciescan serve the interests of another. Thus the arms race can be lostby one party, which means that the result can be a stable state,when one species works in some respects continuously for thebenefit of another, and against his own benefit.8 Many examples arecited in the literature. This is the case e.g. in slavemaking antswho “exploit” the work of ants from other species,9 or the wellknown example of the young of the cuckoo, who gets food from itsfoster-parents. This is against the interest of the foster-parents,who thus have less energy to bring about their own youngs, but isin the interest of the cuckoo, who won the arms race in thisrespect.10

It is presumed, that the manipulation of organisms by eachother is widespread, and this can be the explanation for manyotherwise unexplained, seemingly inadaptive traits or behaviour ofvarious species. Traditionally there was a tendency to explain theseemingly inadaptive behav- iour of a species by presuming that thebehaviour was still somehow adaptive in a hidden way for theanimal. Now we know that real inadaptive forms of behaviour andtraits can exist in species, and they can mean that they lost thearms race in a given respect.11 This situation can be pre- sumed inhumans as well. It can be the case, e.g. that a virus or bacteriumis manipulating our behaviour so, that it will favour the spread ofthe micro-organism, and not our protection. As Dawkinswrites:12

“Is it just an accident that we sneeze when getting a cold, orcould it be a result of manipulation by viruses to increase theirchances of infecting another host? Do any venereal diseasesincrease the libido, even if only by inducing an itch, like extractof Spanish fly?”

We know very little about to what extent species typical humantraits and behaviour are the result of manipulation by otherspecies or by fellow humans. Conceptually, how- ever, those traitsand characteristics which are the results of manipulation, andwhich – by definition – serve exclu- sively the biologicalinterests of another species, cannot be considered healthy, whetherthey are species-typical or not. Thus it is not necessary for thefunctions of an organ to contribute to the organism’s survival andreproduction,

as Boorse thinks, since theoretically many functions of anorgan can serve the interest of other species, they can be theresult of loosing the “arms race” of one species against an otherone.

In contrast with Boorse and the current medical paradigm,which is committed to the species-design view of health,biologically it would be more correct to say that the better anindividual adapts to its environment, the healthier it is. Twoimportant terms are in need of further clarification: “adaptation”and “environment.”

It was widely held, that adaptation biologically was themaximisation of inclusive fitness, i.e., the more an organism’sgenes are represented in the next generation, the more adapted itis. Dawkins13 14 disagrees with this view calling it the view ofthe “selfish organism”, and he convincingly shows, that,biologically, every organ- ism is only a tool for the genes(calling it the view of the “selfish gene”.) Whichever view iscorrect, however, it still remains true that the “function” ofevery organism is to spread the genes of the body. In a certainsense – according to Dawkins – it is not our genes which serve us,but it is us who serve our genes. Every living organ- ism is only atool for the genes to multiply themselves, and every function ofevery organ is subordinated to this “goal”. Thus, it is a mistaketo think, that the function of every organ is serving theindividual. Biologically, the “purpose” of our organs is not oursurvival, but the sur- vival of our genes and our organs help oursurvival only in so far, as this contributes to the survival of ourgenes. Thus the “purpose” of adaptation is the spread of ourgenes.

The other term in the definition, environment, also needs adefinition. In the animal kingdom the environment is given, and forthe animal generally unchangeable. In the case of an animal or aplant it is not appropriate to ask whether the environment, towhich the organism has to adapt, is “good” or “bad”, healthy orunhealthy. In the animal kingdom evolution “uses” the“opportunistic” notion of environment: the environment is alwaysgood, it is always to be accepted, since it cannot be changed bythe animal in the short run, and if it cannot adapt to it, then theproblem is with the animal, who can be called to be diseased, andnot with the environment. So there is a fixed frame of reference inthe animal kingdom, with which we can measure health, and there isnothing inherently value- laden in this concept there. This is – aswe will see – very different from the situation in humans, andtherefore we do not use this opportunistic definition ofhealth.

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As we saw earlier, an evolutionary account of health anddisease necessarily rests on two notions: “adaptation” and“environment”. The meaning of these two notions in humans is notwithout problems.

What does environment mean in the case of humans? Does it meanthe original, primitive environment, in which most of us would notbe able to survive? Or does it mean the modern one, which isextremely diverse in a modern pluralistic democratic society? Themost charac- teristic feature of humans is their tendency totransform their environment in a very short period of time, thusthey have no fixed and unchanging environment. Wild animals andplants normally face a significant change in their environment onlyduring an evolutionary time-scale which is long enough to make itpossible for them to adapt to it biologically. By contrast, humansconsciously trans- form their environment in a relatively shortperiod of time, which is too short to allow biological adaptationto these changes. Since, in the case of humans, the environment isconstantly changing, our species as a whole shows a sort ofmaladaptation to its environment, because it is adapted to a formerenvironment, which only partly exists today. This is a generalproblem of every living organism, but in humans it is much moresevere than in the case of other species. What is more, humancivilisation so radically transforms the environment on the Earth,that the prob- lem of time lag is an ever bigger problem for plantsand animals, too.

Since humans as a species partly choose their envi- ronment,they can consciously transform it, modify it, etc., so they choosethe frame of reference to which they have to adapt. In the case ofhumans we can no longer use the “opportunistic” notion ofenvironment, in which the bad environment cannot be “blamed”. Inthe case of humans we can either say that the individual isunhealthy, or we can say that the chosen environment is unhealthy,to which certain individuals cannot adapt. Thus, if some- bodycannot adapt to his environment (and in the case of human beingsenvironment means a social environment, a certain social structure,institutions, moral-, technical-, etc. standards), it can often besaid that he is diseased, but in some cases it can just as rightlybe said that the environment is unreasonable. E. O. Wilsonwrites:15

“We can be fairly certain that most of the genetic evolu- tionof human social behaviour occurred over the five million yearsprior to civilisation, when the species consisted of sparse,relatively immobile populations of hunter-gatherers. On the otherhand, by far the greater part of cultural evolution has occurredsince the origin of agriculture and cities approximately 10000years ago. Although genetic evolution of some kind con- tinuedduring this latter, historical sprint, it cannot

have fashioned more than a tiny fraction of the traits ofhuman nature. Otherwise surviving hunter-gatherer people woulddiffer genetically to a significant degree from people in advancedindustrial nations, but this is demonstrably not the case.”

The abovementioned fact can explain e.g. an interest- ingphenomenon about phobias in humans. In most cases people havephobias from spiders, rats, snakes, depth, narrow, closed space,etc. which were real dangers in the prehistoric period, and to havean intensive fear from the abovementioned phenomena could havesurvival value in the past. Interestingly people very rarely havephobias from knives, guns, electricity, etc., which are the realdangers in our world today.16 It is evident that phobias, arereflecting our past environment, they were adaptive then, but arehighly dysfunctional in our present one. If we compare how manychildren die in a year in a modern society, because of snake-bite,and how many because they are run over by cars, we would say, thatcars repre- sent a much greater danger to them than snakes, andstill children fear snakes more, than cars. We can either call thislack of natural cautiousness from cars abnormal, or we can say thatthe rules of contemporary societies, which do not do enough againstcar accidents, are unreasonable and have to be changed.

The classical medical model, which defines disease as thedisturbance of the adaptation to the environment, gives theimplicit apology of the given environment. The word “disease”namely indicates the characteristic notion in the body-environmentrelationship which has to be changed. If the relationship betweenthe body and the environment is inadequate, and the body isconsidered to be diseased, this means that the environment isacceptable and the body has to be changed. But if health is thedesirable rela- tionship between the body and the environment, andif this relationship is undesirable, and the environment can bechanged, it is theoretically a question of view-point whether wecall the body or the environment as diseased. E.g. todayvaccination is required from travellers, who wish to go to a partof the world where some serious infectious diseases are endemic.Without inoculation the majority of travellers would surely catchthe infection and many of them would die, because they do not havethe natural resistance against these infections. Still we usuallydo not think them to be diseased, but rather, we think that theenvironment to which they wish to go, is unhealthy, and they mustbe protected against it. A similar example is that of a homelessperson who freezes to death in a very cold night. We would not saythat he was unhealthy, because he was not able to endure thesubzero tempera- tures, but we usually blame the welfare net of thesociety, the lack of social institutions taking care of thehomeless, etc.

Thus a number of inadequate relationship between the body (ormind) and its environment can be described

as the “disease” of the environment, which is, on the otherhand, the apology of the given physical or mental state, andrequests to the alteration of the environment. In many cases, whenthe undesired relationship between the body and its environment isconsidered to be a disease according to the medical model, there isa possibility of an equivalent sociological description, whichconsiders the environment to be “diseased”, to be unreasonable.This is why a great part of medical problems can also be defined asenvironmental ones, and thus become ecological and social ones.Medicine, as a matter of fact, is the criticism of the body. Itsattitude can be put in this way: there is something wrong with thatbody or mind, which is unable to adapt to its environment. Thesociological approach would be as follows: there is something wrongwith that society, to which human beings with some given physicalor mental characteristics are not able to adapt.

The tendency of our age is medicalisation, i.e. orig- inallynon-medical problems are defined by medical ter- minology and arethought to be solvable by means of medicine. The above-mentionedother point of view, which defines medical problems by theterminology of sociology, and considers them in many cases associal ones to be solvable partially or totally by social means,could be called sociologisation, and is much less spread nowadays.The reason for this may be the more developed state of the naturalsciences compared to the social sci- ences, and the fact thatsocial problems seem to be more manageable, if they are describedas medical ones, and not as political or social problems.

The other term in the definition of health, “adaptation”cannot be applied to humans without some modifications, either.What is the purpose of adaptation in humans cul- turally? It isevident, that human beings generally do not see the spread of theirgenes as their major goal, but longevity, happiness, knowledge,etc. The widespread practice of contraception and abortion atteststo it that the conscious goals of individuals and cultures aredifferent from the biological “telos” of human organisms. From acultural point of view not those human organisms are thehealthiest, who are capable of attaining the biologi- cal “aims” ofthese organisms (i.e. the greatest possible spread of their genes),but those, who are capable of attain- ing the goals set by thesociety, or in a more democratic and individualistic society, thegoals set by the individuals themselves. While the biologicalnotion of health express- es how efficiently the body and the mindof an individual can be “used” by the genes for their ownmultiplication, the cultural notion of health expresses howefficiently the body and mind can be used as tools to realisecertain pre- ferred ways of living, values, and standards, desiredby a given culture or individual.

In summary, in case of humans, both the notion of environment(which we choose and create), and the notion of adaptation (the aimof which must be defined, as it dif-

fers from the biological aim of maximising one’s inclusivefitness) are inherently value-laden. Since these notions areindispensable to any correct definition of health, we must concludethat any definition of health in humans is necessarily value-ladenas well. Nevertheless, the posi- tion of Boorse is a nearly correctdescription of the actual medical usage of the term “disease”, andif it is to be criti- cised, this would imply the criticism of thecontemporary medical thinking as well.

As we saw earlier, Boorse’ s account of the definition ofhealth is at odds with the spirit of contemporary evo- lutionarytheory. Thus, the species-design view of health, which is theparadigm of contemporary medical think- ing, is also at odds withmodern evolutionary biology. What can be the cause of thisdifference between the paradigm of biology and medicine? One reasonis evi- dently epistemological. Since the only sure evidence forthe fact that an organism is healthy, is, that it has adapted wellto its environment (whatever we mean under the notion ofadaptation), and since the human environment is constantlychanging, we simply cannot know in advance which characteristicswill be optimal at the adaptation to the new environment. Thus, topredict this, medicine has to rely on the only available data ithas, i.e. what rep- resented the best adaptation in the past. As wesaw, this procedure is a correct method of prediction only insofaras the environment is fixed, and it is incorrect insofar as theenvironment changes. As the typical feature of our presentenvironment is its radically changing character, this method isless and less correct at present. E.g. How can we know whatfeatures of the human body are the most advantageous for survivalin a polluted urban envi- ronment today? Our lungs, immune system,etc. were surely not “planned” to inhale the exhaust-gases of mod-ern cars, so we can be sure that a species-typical lung, enzymesystem etc. are not the ones which ensure the best survival in thisenvironment. There is bound to be some difference among people interms of their resistance against the carcinogenic effects of thesefactors in our environment, but we know very little about it. Thusmedi- cine – if it lacks the reliable data – still often presumes,that the species typical characteristics will provide the bestsurvival. This is understandable but is surely false in many casesfrom a theoretical point of view. Only carefully plannedstatistical studies can provide evidence, which characteristics inwhich environmental situation seem to be the healthiest, but by thetime the result of the study emerges, new cars, new carcinogensemerge, which change the situation again, and it is probable thatother bodily characteristics, parameters, etc. will ensure the bestsurvival, than was shown by the previous study.

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Within normative theories of health and disease Sadedistinguishes subjectivist and objectivist theories. In asubjectivist theory values are relative, they are simply subjectivedesires and wants so there is “ no stan- dard by which tojudge the desire’s appropriateness or goodness”.17 In an objectvisttheory, by contrast, values are moral goods, they are objective andthey are desired because they are good. In short, in a subjectivisttheory something is good, because it is desired, while in an objec-tivist theory something is desired, because it is good.18 Sade’sown view of health and disease, which is a refined version of thatof Lennox, belongs to the objectivist theo- ries of health.According to