Abstract
Throughout human history, individuals have had to contend with the rigours of simply being alive. This has typically required the help and assistance of others - not least during times of being unwell. Modern scientific medicine may be seen as the latest, most intellectually and technologically advanced of all the ways in which assistance with making life more tolerable has been afforded. This comes after a long history of subtly changing conceptions about what is happening to the body primarily in relation to disease. Knowing when - or, indeed whether - to treat any of a plethora of different physical and mental conditions is of paramount importance to the modern clinician. Knowing when to cease treatment can be equally important. Therefore, it is important to have a notion of health as this can act as a standard against which to gauge a patient's condition. Yet, despite its apparent simplicity, defining what health might be has proved to be an almost intractable problem. This is despite concerted attempts by a range of thinkers including philosophers as well as clinicians. Intuitively, simplistic linear notions - such as those juxtaposing health and disease by placing them at opposite ends of a single axis - are often encountered and seem to represent a prevailing attitude. However, such notions fail to give full consideration to the range of factors influencing a patient's condition. Despite being much criticised, the World Health Organization definition of health as 'a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity' does, at least, recognise the complexity of health. As such, there are physical, experiential and behavioural dimensions that any definition of health must bring into consideration.
Having a concept of 'health' is important in the identification, treatment and non-treatment of a wide range of physical and mental conditions. Knowing when to treat, when not to treat, and when to cease treating is important for the provision of proper ethical patient care. Appropriate non-intervention can be as important as appropriate intervention. Furthermore, wastefulness – not to mention patient distress – ensues when responses are made needlessly to subtle deviations from the norm. A better understanding of health may help limit unnecessary interventions and limit some of the unrealistic expectations increasingly being placed upon healthcare providers. Furthermore, the goals and limits of individual therapies and of medicine as a whole may become clearer.
However, defining health appears to be a simple, even unnecessary, matter that does not spark the interest of most healthcare workers. Everybody knows what health is – that is, until they are asked to provide a clear and concise definition of the word. Not only is it hard to provide such a definition but, if past experience is anything to go by, those devised are unlikely to stand up to critical scrutiny well enough to gain general approval. However, that is no reason to stop trying. Perhaps the approaches taken in the past have been misdirected.
1 Concerted Attempts
Under the editorship of Richard Smith, the British Medical Journal, in press and online, has, over a number of years, continued to raise the question of how health might be described or defined. As Smith notes in a BMJ blog:
'Last week about 30 of us spent 36 hours in The Hague discussing whether we could produce a new definition of health—and eventually deciding that we couldn’t.'
A brief account of these deliberations eventually appeared in the British Medical Journal (Huber et al 2011) where, taking a lead from environmental science, the authors suggested that health might be 'the ability to adapt and to self manage'. Or, at least, '[t]his could be a starting point for a ... fresh 21st century way of conceptualising human health'.
As Smith also noted, when it comes to asking what health is '(f)or most doctors that’s an uninteresting question'. As he goes on to state '[d]octors are interested in disease, not health. Medical textbooks are a massive catalogue of diseases.' So, perhaps thinkers have been coming at this problem from the wrong angle. 'Health' and 'disease' are the two most fundamental terms in medicine. Intuitively, they form the polar opposites between which medicine is practised. Combating one and ensuring or restoring the other is the mainstay of clinical practice. So perhaps the question of health might be assailable via disease.
However, defining what disease might be seems equally difficult as studies also published in the BMJ have discovered (Campbell et al., 1979; Smith, 2002). Offered a list of named conditions with which clinicians frequently deal, different groups of people – including medical academics and general practitioners – were asked which they considered to be diseases and which they thought were not. The specific results are, perhaps, less significant than the overall findings that, noticeably, complete agreement was lacking. There were differences of opinion both within and between the groups surveyed. Clearly, deciding whether something merits being called a 'disease' is not a simple proposition.
2 Each End of a Line?
Often, when health and disease are represented graphically, they are shown at opposite ends of a line. A horizontal line typically has disease to the left and health to the right. A vertical line has disease at the bottom and health at the top. In adopting this approach, there is clearly a tacit inclusion of value judgement: health is being equated with the conventionally more positive ends of these lines; disease with the less positive, or negative, ends.
In these representations, there is also an underlying assumption that disease is continuous with health. For this to be the case, both disease and health must be commensurable. That is, they must be capable of being measured by the same common standard. That this is the case has never been established. What can be said to be commensurable and so part of a continuity is how one feels: one's experience of ease or unease (Antonovsky, 1980). One may say that one feels 'well' or 'unwell' or perhaps somewhere in between.
Here it is important to make a distinction between experience and physical state. This seems to be easily and frequently overlooked. Both are integral to being an individual. One may feel well but have potentially life-threatening physical lesions. One may feel quite unwell but without any discernible physical reason (Marinker, 1975). In the former scenario, one is able to go about one's daily life unhampered. In the latter, one will not be able to go about one's daily life quite so well. How life is led is determined to a large extent by how one feels rather than by how one might be physically. Any definition or conceptualisation of health and disease must, therefore, take this into account.
3 A Wider Debate
Among philosophers of medicine there has been considerable debate about the definitions of both 'health' and 'disease'. Philosophical interest began, arguably, within the medical profession in the years which followed the founding of the WHO and was perhaps inspired by its founding definition that
'health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.' (WHO, 2006)
However, a more intense debate about the definitions of 'health' and 'disease' has continued since the mid-1970s when Christopher Boorse published a brief series of articles (notably Boorse, 1975, 1976, 1977). Contrary to the WHO definition, Boorse saw no problem in defining health as the absence of disease. In so doing, he also proposed the Bio-Statistical Theory of disease (BST) which posits disease as a statistical deviation from an average functional state.
However, despite mounting a vigorous defence (Boorse, 1997), most of those who have responded to his ideas have responded negatively to the point that it has been proposed that the BST should be considered to have been refuted (Khushf, 2007). For all the negative comment and claims of refutation, the BST somehow lingers on. The reason for this may lie in the fact that it reflects something of prevailing medical thought. It was Boorse's intention to extract a definition of disease from what clinicians were thinking. His was primarily a philosophical task. If the definition Boorse gives in the BST is flawed, it is perhaps because the thinking he has crystallised is also flawed. This is not to imply that medical thinking is entirely wrong but that it might be improved upon.
4 Schools of Thought
There are many identifiable nuances of opinion regarding the concepts of 'health' and 'disease' which may be teased out from writings on the subject (Hofmann, 2001). However, Nordenfelt (1986) has suggested that there are two broadly identifiable schools of thought. There are those who hold that objective (value-free) definitions of 'health' and 'disease' can be found via a scientific approach to the workings of the body. It holds that 'health' and 'disease' can be understood in largely physical terms. This school of thought, often described as 'naturalism', is represented by Boorse. Alternatively, others hold that such definitions are inherently non-scientific, value judgements. This school of thought, often described as 'normativism', has come to be associated with the work of Lennart Nordenfelt himself (Khushf, 2007).
Nordenfelt has approached the definition of 'health' from the perspective of action theory. Of central importance here is the individual's ability to achieve various 'vital goals' associated with daily living. By 'vital goals', Nordenfelt is referring to those of an individual's needs that have the highest priority. Thus, his definition of health becomes that state '[w]hen the individual A is in a bodily and mental state which is such that A has the second-order ability to realize all his or her vital goals given a set of standard or otherwise reasonable conditions' (Nordenfelt, 2006). Although philosophically more precise, this definition is less memorable than the much criticised WHO definition.
While there is a clear contrast between Boorse's and Nordenfelt's approaches, importantly, the bipartite division between their two schools of thought is not rigid. It does not follow that one is exclusively a 'naturalist' or a 'normativist' for all medical conditions. It has been suggested that one can be a naturalist regarding physical conditions and a normativist regarding psychiatric conditions (Murphy, 2009). Boorse focuses upon the function of parts of the body whereas Nordenfelt focuses upon the ability of an individual to live out their life. Considered separately, there is in each something with which clinicians can find agreement. However, when considered together, one perhaps begins to notice how distinct each approach is. Thus, it appears that both the schools of thought have something to offer. Yet, a unification of the two approaches has not been possible, so far.
5 To Define or To Conceive
Much emphasis has been placed upon trying to find a verbal definition of 'health' and 'disease'. Here 'health' and 'disease' tend to be treated objectively as if they were, in philosophical terms, 'natural kinds'. A 'natural kind' is something that exists in nature independent of human categorisation. One of the core questions that needs to be asked is whether that debate has adopted the most appropriate approach. Instead of verbal definitions there might yet be an alternative approach which may prove to be more successful in revealing what the words 'health' and 'disease' represent. An approach that is able to provide something akin to a definition without being burdened with the difficulties that worded formulations experience.
If clinicians are unable to offer neat and precise verbal definitions of 'health' and 'disease', it may not necessarily be because they do not know intuitively what they are dealing with. Instead, it may perhaps be because providing definitions of this kind is the wrong approach. Not everything is done in accordance with verbal codifications. Much relies upon mental images – pictures and conceptualisations. Instead of trying to describe 'health' or 'disease' in words, perhaps one should be trying to paint a picture of what they are. Here the image of humanity prevailing at any given moment in time can have a direct bearing upon how health and disease might be understood.
6 The View from History
Although there is a continuity with the healing traditions in the ancient world, the scientific bases upon which modern western medicine are built are of only fairly recent origin. Furthermore, the roots of medicine go much deeper than is usually realised. While the Greco-Roman world gave written form to much of what was to influence European medicine for over fifteen hundred years, medical practice, in its broadest form, has existed since human pre-history. Dating from around 6500BC, archaeological evidence exists for the practice of trepanning. This early form of quite hazardous surgery was performed skilfully with only rudimentary instruments. The openings produced in the skull were carefully sculpted and were clearly not fatal. Subjects certainly survived for some time following surgery as bone edges have been found which show evidence of new bone formation. Furthermore, it was a practice for which evidence can be found in both the old and new worlds suggesting perhaps a very ancient common ancestry. Exactly why such a procedure was performed is not entirely clear – skull trauma does not seem to have been the reason. The practice points instead, perhaps, to the existence of medical cosmologies lost in pre-history. Significantly, it points to a system of care within early human groups and to the existence of individuals who had acquired considerable skills. It may also point to the beginnings of the enduring notion that disease is a distinct entity which needs to be encountered – even extracted or released from the body. The trepanned skulls may have been opened to allow something to escape. By this one does not necessarily mean a sub-dural haemotoma or an embedded bone fragment. Instead it may have been some supposed entity such as a controlling spirit which required exit.
Throughout the whole of human history, others have been called upon to provide assistance with what might be described as 'quality of life' issues and with staying alive in general. That continues to be the case throughout the world today. Individuals identified as healers are known in all societies whether they be shamans, witch doctors, medicine men or members of the medical and allied professions. These are those from whom help is sought for a whole host of issues associated with the problems of life.
7 Ascent to Science
Auguste Comte (1798-1857) suggested that there were three phases to the development of any society or field of knowledge. These were the theological, the metaphysical (or abstract) and finally the positive (or scientific) stage. Using Comte's phases as a rough guide, it is possible to envisage the history of medicine along similar lines. However, instead of considering medicine to have begun in the ancient world of Greece and Rome – which, instead, more closely equates to the start of Comte's second, metaphysical, phase – the pre-historical period with its shamanism and other appeals to the supernatural belong more properly to the theological phase. It was then that appeals to supernatural realms and explanations in terms of oppressive spirits or demons were not uncommon. Although echoes of this persisted into Ancient Greek medical thought – and even into the modern day – much of medicine's Comtean theological phase has been lost to pre-history.
Medicine's metaphysical phase was largely spent in the shadow of Galen (129-199/217). It was not a period entirely in the doldrums but neither was it a period of significant technical or conceptual advancement. Medicine's metaphysical phase was one also coloured by astrology and alchemy. At its end, change was to come about largely as a result of the work of the physician-academics of the sixteenth and seventeenth centuries. In particular, the observation-based anatomy of Andreas Vesalius (1514-1564) and the nascent physiology of William Harvey (1578-1657) set the scene for what was soon to follow. Observation and experimentation began to take preference over the customary deference to the authority of the ancients.
Two important conceptual innovations of particular note in medicine occurred during the seventeenth and eighteenth centuries. In the mid-seventeenth century, Thomas Sydenham (1624-1689) – the so-called 'English Hippocrates' for his mastery of medicine – formulated a concept of disease that still circulates in one form or another today. His view – for it could not be based upon rigorous scientific evidence at that time – was that diseases were distinct entities (Bynum, 1993). His conceptual system of disease – his nosology – held that diseases were natural kinds; they could be classified into a taxonomic system in much the same way that Linnaeus (Carl von Linné (1707-1778)) classified plants and animals. Indeed, Linnaeus was also to propose such a system in his 'Genera Morborum' (1763). This attitude, which was probably held in various forms from pre-historic times, now found formal and respectable expression.
8 The Dawn of Modern Medicine
Sydenham was particularly innovative in seeking to give a full description or picture of the objective characteristics of each disease as presented by the patient. Thus, he advocated what might be described as a 'natural history' approach to disease, detailing how each progressed in different patients. Significantly, it is to the work of Giovanni Battista Morgagni (1682-1771) that modern pathology as a scientific discipline can be traced. Indeed, Morgagni has been called the father of modern pathology. In 1761, Morgagni published 'De sedibus et causis morborum per anatomem indagatis'. The title translates as 'On the seats and causes of disease investigated by anatomy'. In it, Morgagni also took a 'natural (or medical) history' approach reporting case studies of patients upon whom autopsies were performed. His intention was to relate post mortem findings with the symptoms reported during life. In so doing, Morgagni provided the physical foundation that Sydenham's nosology had lacked. It was reckoned that within the body of the patient, there was something which could be physically located and which could be held responsible for their ailments. From here, it was a simple step to assuming that physical lesions were tantamount to diseases per se. Subsequently, in the nineteenth century, the focus shifted from the visible lesions that Morgagni had located to alterations in tissues, as described by Marie François Xavier Bichat (1771–1802) using a magnifying glass and then to cells, as observed by Rudolf Ludwig Karl Virchow (1821–1902) using microscopy.
During the twentieth century, this increasingly reductionist approach reached gene level. Where individuals, organs, tissues and cells could once be described as diseased – and the word 'healthy' is applied in a similar way – the same could not be applied to genes. It is clearly inappropriate to refer to 'diseased genes' – which are, after all only chemical strings – in the same way that one refers to a 'diseased liver', for example. Disease, at least, is a term that can be applied only to something that is alive. The situation is less clear for health. Foods and certain forms of behaviour have increasingly come to be described as 'healthy' or 'unhealthy', perhaps complicating the problem of definition.
9 What's in a Word?
Etymologically, the word 'disease' literally means a loss or lack of ease – that is, 'un-ease'. It previously described what is now more often implied by the word ‘illness’. This contrasts interestingly with what the WHO definition counsels against: that health not be seen as merely an absence of disease. Disease was originally an absence: an absence of ease. In English, the earliest use of the word ‘disease’ dates from the early fourteenth century and simply meant ‘discomfort’, having been derived from the old French ‘desaise’ which meant much the same. By the late fourteenth century, however, it had already come to be used in the sense of being unwell or ailing but its literal sense of general discomfort seems to have continued until the early seventeenth century (Lewis, 2011).
Recognising the difference between disease as a 'loss-of-ease' and disease as something with some sort of physical basis is an important metaphysical issue for medicine for it relates directly to what may be understood as health. If disease is seen as an entity which merely resides at a specific location within an otherwise healthy individual, then removal of the offending lesion is all that is necessary for the restoration of the patient to full health. Here, health is seen as an individual's default or normal state. However, if somebody is suffering because of what emanates or results from a lesion, then this is something with broader effect. In this case, removal of the lesion may only be part of a wider approach to treatment and cure requiring a more general systemic realignment of a range of interconnected bodily processes.
10 Conclusion
When trying to define health, what appears at first sight to be quite simple, soon becomes quite complex and seemingly intractable. In the past, to feel well was taken to be much the same as being healthy. Now, with the introduction of more analytical scientific thinking which seeks material explanations within the substance of the body, attention has shifted. While this has been going on, no accompanying conceptual change has occurred. Instead, word usage appears to have become more complicated rather than simplified by greater understanding.
In trying to understand what health might be, the first task must be to recognise that this Gordian knot is made up of different threads. Health has an experiential dimension in how one feels, it has a physical dimension in how one is constituted and it has a behavioural dimension in how one is able to go about the activities of daily life. To some extent, the three-part core of the WHO definition recognises this. In another sense, it does not go deeply enough and much remains to be done.
Acknowledgements
I would like to thank Annette Lewis for her help in the preparation of the manuscript of this chapter.
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