I do not think anything I shall say is new; much of it has been better said before, and some of it is very old-so old indeed that there always is a chance it may be mistaken for new. But I am encouraged to hope that, even so, it may fulfill the terms of the Bradshaw Trust, which states simply that a lecture shall be given in memory of Dr. William Wood Bradshaw on a subject connected with medicine or surgery.
As a starting-point I propose to try to put into words some ideas about the nature of disease which seemed to be taken for granted in the medicine I was taught nearly twenty-five years ago. It was assumed, so far as I could see, that there were things or entities called diseases, which could be studied and treated as such. Some of these arose in and affected the mind, and were the province of psychiatrists. Others arose in and affected the body, and were the province of physicians, surgeons, and various specialists.
Diseases with physical manifestations could be divided into organic and functional. Organic diseases were regarded as real, objective, and the proper object of study by scientific medicine. They had physical causes, which either had been or would be elucidated as a result of increasingly thorough study by physical chemical, and bacteriological methods. In the investigation of a disease the object was to find “the cause” and to deal with it. There was little or no interest in functional disorder. Functional symptoms seemed usually to be regarded either as invented or imaginary or as rather mysterious and discreditable states which in some way affected inferior personalities.
I do not think, as a student, I heard the word “psychosomatic”, which is not surprising, for this actual word was apparently first used in 1926. Within a few years, however, it was suggested that certain physical diseases for which no satisfactory cause could be found, and which were becoming increasingly noticeable as important sources of disability, were psychosomatic in nature.
This appeared to mean that the structural changes found in the body were caused by a disordered mind. This possibility was eagerly seized on by a few, but denied or ignored by the many who believed that real organic disease had little or nothing to do with the mind and would ultimately yield its secrets to the methods of physics, chemistry, and bacteriology.
Though stated baldly and perhaps over simplified, I believe that is a fair summary of some of the main ideas about disease which were more or less taken for granted in the medicine I was taught. If any of my teachers should say they took nothing of the kind for granted, I can only say that this was what an average student gathered, not so much perhaps from what they said as from what they did not say.
One saw, of course, that many of ones teachers did treat their patients as persons rather than as mere vehicles of disease, but I believe this was more an expression of humanity than an indication that they accepted such an approach as necessary to the understanding of disease.
Ideas still taken for granted
I believe that some at least of the ideas I have outlined are still taken for granted by many persons engaged in academic medicine, by which for the purpose of this lecture I mean medicine as taught in under-graduate teaching schools. I will not waste time in defending this latter statement at length, but would refer to two recent articles by eminent teachers in under- graduate schools.
The one lists what he calls the five common causes of disease; in born and inherited abnormalities; excess of a chemical agent in the environment; deficiency of a chemical substance; infection or infestation by viruses, bacteria, fungi, or animal parasites; and physical trauma. He thinks it possible that the important diseases of unknown aetiology, such as the rheumatic diseases, peptic ulceration, and ulcerative colitis, will turn out to be due to these same causes, acting singly or in combination but entertains the “possibility that there exists a group or groups of diseases the causation of which we do not comprehend, or comprehend but dimly.”
His statement of what he calls the psychosomatic hypothesis which is at least commendably brief is that it “attributes disease to certain abnormal states of the mind.” This hypothesis is then immediately dismissed along with that of focal sepsis as unworthy of serious consideration by scientific medicine. “The small amount of critically established fact”, he says “on which these two hypothesis were based can probably be accounted for on the fact that the condition of any patient suffering from a chronic disease deteriorates when there is superadded infection or disturbance of the mind” (Pickering, 1950).
The other, speaking of the place of psychotherapy in the treatment of peptic ulcer says: “In this connection it should be recognized that, while many neurotics invent digestive disturbances, the ranks of genuine ulcer cases contain no higher proportion of neurotics than does the population at large. Most ulcer patients, indeed, are the reverse of neurotic. They may be anxious and worried, but they never invent symptoms, generally make light of their suffering, and rarely give up work unless the pain is intolerable” (Illingworth, 1952).
I would like to assure the authors of these in many ways admirable lectures that I have picked on theirs out of many others I could have chosen, not from any personal animosity, but simply because they happen to illustrate my thesis that certain ideas which seemed implicit in what I was taught are still current in academic medicine to-day.
I believe these ideas are almost without exception open to serious objections. I shall now examine some of them further, and in doing so review in an admittedly eclectic manner some paper which seems to me to illustrate changing ideas. In particular I wish to examine a common misapprehension that there is something called the psychosomatic hypothesis, which holds that abnormal mental states can cause physical disease. This will involve at least some references to the idea of diseases as entities, to the idea of cause in medicine, and to the problem of the relationship between mind and body.
It was and often still is assumed that there are entities called diseases which can be studied and treated as such. But if we think about it, it seems obvious that we cannot observe diseases; we can only observe diseased persons during life or the mortal remains of diseased persons after death.
Nosological classification may be a necessary convenience for purposes of orderly description, but we have come to think and often to act as if the states it describes exists as entities which can be studied and health with apart from the person who is diseased. One might almost feel one had to apologize for mentioning some thing so apparently trite and obvious were it not that much current teaching and action appears to be based on the opposite assumption.
Causes in Relation to Medicine.
I have already said that it seemed to be assumed, when I was a student, that organic diseases had physical causes, and by this there was often implied a single cause, The cause of lobar pneumonia was the pneumococcus. The cause of cirrhosis was alcohol, and so on. The business of diagnosis was to find the cause of the disease, and the object of rational treatment was to remove it. When the cause was unknown, only symptomatic or empirical treatment was possible. I have perhaps laboured these illustrations to show that we really did seem to think in terms of single causes, though we cannot have gone very far in considering the implications of this view.
The idea of cause is a complicated one, and many people much better qualified to do so than I have written about it relation to medicine. However (1934), for instance, speaking of the kind of examples of cause and effect I have just mentioned, says: “However, not one of these examples is truly a case of cause and effect. Not only is the effect antecedent events, but each of these antecedent events is produced by the interaction of another two.
If we are to be accurate we must than recognize not a cause but an endless multiplicity of causation, which is extremely confusing. There never is, in fact, a cause but always relationship. And a little later on he says: “It is today generally agreed in theory, although not always recognized in practice, that disease is essentially an interaction between seed and soil, in both of which there is a convergence of a sequence of related events, from the association of which the effect is developed.”
What we can observe, he says, is a series of events connected and related through the medium of time, stretching back into the past and forward into the future. If a bus runs over my leg I may say that the impact of the bus is the cause of the fracture of my femur. More accurately, the event may be described as the intersection of two time sequences in which the bus time-sequence crosses the leg time-sequence. “If we seek causes we find two causal time chains: what caused the bus to do as he did; what caused the leg to be where it was, and what caused the leg eventually to heal. These are not truly to be regarded as being causes, but as a series of related time-effects.”
Recently Strauss (1952) devoted the first of his Croonian Lectures to a discussion of causality in medicine. I am afraid that many of the ill-educated generation to which I belong may have found his philosophical arguments difficult to follow. But we cannot fail to appreciate his criticism of rigid causal relationship in medicine and to be convinced of the inadequacy of our search for single or “specific” causes of disease. I cannot, however, resist one or two comments.
“It is arguable”, says Strauss, “that a pure paired cause-effect relationship exists at two levels only: the ethical and the mechanical.” Of the pure paired cause-effect complex at the mechanical level he gives two examples; a person swallowing a large amount of arsenic by mistake the cause leading to the acute gastritis the effect; and a second example, a personal experience of his own, of the sudden protrusion of a lumbar intervertebral disk the cause leading to severe pain in the back and complete immobilization below the waist the effect.
These examples of simple cause and effect at a mechanical level are then contrasted with an account of the possible factors bacteriological, constitutional, sociological, and psychological concerned in the development by a particular person of the mode of morbid behaviour which we call pulmonary tuberculosis. The contrast is instructive, but one is compelled to ask whether in the two examples cited the effect can really be attributed to a single mechanical cause.
I would like, for instance, to know how the “mistake” (which Strauss agrees in an over-simplification) of swallowing the arsenic occurred, and I would suggest the effect might have been different had the subject by some odd but not impossible chance been a habitual arsenic eater with a tolerance to the drug, such as has apparently been observed in Styrian woodcutters. Should not the effect in this case again be regarded as resulting from the convergence of two sequence of events what caused the arsenic to be where it was and to be swallowed, and what caused the person who took it to be susceptible to its effects?
A personal experience.
The second example interests me, also on account of a personal experience. I too suffered from a pain in my back in this instance a chronic pain over many years severe enough to be a nuisance at times, but never incapacitating or bad enough to make me do anything about it. In the earlier years I supposed it was due to fibrositis, whatever that is, and encouraged by dentist to look for a source of focal sepsis, which he did not find. Some years later, when it was particularly troublesome in humid tropical climate.
I supposed that constantly damp clothes and bedclothes had something to do with it. Later, after regarding about psychogenic backache, I concluded this must be whole explanation. Some months ago an x-ray film of the spine showed, I am told, conclusive evidence of an old and considerable protrusion of a lumbar intervertebral disk. Here, surely, was another example of direct mechanical cause and effect, and incidentally a vindication of the importance of searching for a single demonstrable cause for a symptom or group of symptoms, rather than indulging in the vague speculations of multiple aetiology.
But I am not so sure, for I believe that the protrusion of my disk was not entirely an accident; and, further, I have to account for the fact that I have for some time been particularly free from pain, though I am assured that the actual disk lesion is unlikely to have altered.
Briefly and if you will forgive some personal details I believe the protrusion of my disk can be traced back to two what might be called parlour tricks. The first was to challenge my fellows to put their hands flat on the ground in the front of them without bending their knees. This, the only faintly distinctive physical achievement I had, used to give me satisfaction, and was probably harmless. Unfortunately some years latter, though I had never been able to jump anything, I discovered I could do what is known in gymnastic circles as a “neck-roll.” This consists in diving over some object, turning a somersault on a cushion or mat, and landing one ones feet again. It was a great success at Army mess nights and similar occasions.
Unfortunately it involved sharp flexion of the lumbar spine, and after a year or two I had to abandon it on account of increasing pain and stiffness in my lower back. I have little doubt this eccentricity was an important factor in the protrusion of my disk and, of course, the story could easily be pursued further by inquiring why a clumsy and rather obese physician should have found it necessary to perform “neck-rolls” at an age when such an accomplishment is not generally considered necessary but I do not intend to follow it further on this occasion. I have said enough to indicate that I am fairly sure the protrusion of my disk was not a simple mechanical accident.
Once it was discovered I was given some back-extention exercises and advised to wear lumbo sacral support. This contrivance supports nothing except any abdominal protrusion which may be present, but is effective because it makes bending so uncomfortable that one ceases to bend. I preserved with the belt and the exercises for at most a week or two. I was virtually free from pain within a few days and have now learnt that I can remain so without the aid of the support or the exercises, so long as I do not habitually slump in chairs and seats. When I do so slump, I get a slight return of pain, I have no doubt that for me “slumping” as I have called it, is a physical expression of certain emotional attitude.
I have troubled you with this rather long personal anecdote because it seems to me to illustrate clearly the inadequacy of the idea of single causes. For you will see that if you were to ask me what was “the cause” of the pain in my back I should find the question difficult to answer.
What we call the cause of an illness is never strictly the whole cause, though it may be a necessary factor in causation in the sense that one would not have that particular illness without that particular factor. I would not have had the particular kind of pain in my back if I had not had a protrusion of an intervertebral disk. But the protrusion of the disk was simply one link in a chain of causation, and the pain, once it was understood, was relieved by fairly simple measures, which presumably left the disk lesion in situ.
It is worth noticing, perhaps, that the main difference between these two examples of the protrusion of a disk is that the first might be described as an acute illness and the second as a chronic. This is probably an example of a general difference, to which attention has often been drawn, as for instance by Ryle (1942). Whether or no the search for single or specific causes is ever justified on philosophical grounds, it has been more productive of results in acute than in chronic diseases.
Medicines greatest successes have been in connection with acute disease and particularly acute infections. Where partial success has been achieved in the treatment of chronic diseases, as in myxoedema, diabetes, and pernicious anaemia, one must note that in each instance the patient is not cured, and our knowledge of the aetiology of the condition is still white incomplete. Our ability to deal successfully with most chronic diseases has advanced much more slowly than in the case of acute ones, and it is possible that this is due, at least in part, to our undue preoccupation with single specific causes and direct mechanical cause and effect.
Aetiology in Relation to Medicine.
Aetiology is defined in the Oxford Dictionary as “the science or philosophy of causation” and in Dorlands Medical Dictionary as “the sum of knowledge regarding causes.” Strauss has described the substitution of the term “aetiology” for “cause” as no more than a resort to the magic of semantics in an attempt to escape from the fetters of rigid causality. But I believe that the change in words can be something more than semantic juggling and may represent a change both in ways of thinking and in ways of acting, which is to be encouraged even though we are still far from a satisfactory concept of aetiology.
Ryle (1942), after quoting the definitions I have mentioned, continued: “it is well to insist on such definitions, for the discovery by Pasteur and the great pioneers in bacteriology of specific microbic agents of disease, and the recognition by others of specific chemical agents and specific deficiencies, have until quite recently and contemporaneously with their immense benefits to medicine, had a peculiarly limiting effect upon the vision and the practice of many medical men, not excluding teachers. They have, in fact, compelled a neglect of the associated causal factors without which no disease can have its being. They have also fostered a belief in or search for single determining causes where none exist.”
A paper by Halliday (1943) seems to me of particular value in that, though some difficult matters are perhaps over simplified, the author outlines a concept of etiology which seems to avoid obvious pitfalls and to provide a reasonable system of thought on which medical action can be based. In the space available I can do scant justice to this paper, which could with profit be read, pondered, and re-read by every teachers of medicine.
Cause in medicine, says Halliday, has usually been regarded in one of two ways; and he calls them the “mechanismic” and the “biological”.
The word mechanism refers to a system of mutually adapted parts working together as a machine. Given the requisite preceding movement, the ensuing movement follows necessarily upon it, provided the machine is in working order. During the last three centuries, knowledge of the human organism in terms of mechanism increased progressively and the organism came to be regarded as if it were in actual fact a machine.
If it failed to function properly, the cause of the breakdown was similar to that of a machine that is, a fault in one or more of the component bits and pieces. The primary concern of medicine was to identify the fault, which might be viewed by any technique for example, gastric ulcer, a structural fault; acidosis, a chemical fault; or hypertension, a physical fault and to take appropriate action by interfering with the mechanism.
Some of the implications of mechanismic aetiology Halliday summarized as follows: (1) The human organism is a machine composed of mutually adjusted parts working together. (2) Illness corresponds to breakdown in the machine. (3) The cause of illness (provided the patient has adequate food, air and water) is some thing wrong a fault, disease, lesion, imbalance, or abnormality in one or more of the parts. (4) Medical action is confined to interfering with the mechanism by what is known as the appropriate treatment.
This mechanismic attitude has, of course, brought great advances. The criticism of it is not so much that it is wrong as that it is not enough. In particular it gives little or no guide to action in the prevention of disease, for it is concerned with how a patient is ill rather than why he is ill. One might add that while few doctors now take a purely mechanismic view, most patients do, hence the very great difficulty of giving them any reasonable explanation of functional symptoms.
Say what we will, the patient believes there must be a fault in the mechanism somewhere “the cause” and an appropriate means of dealing with it “the cure”. One might also point out that the mechanismic idea of disease allows of no definition of health other than the absence of disease, which is plainly inadequate, for there is a great difference between “no disease” and health.
Halliday explains what he calls the biological idea of cause as follows. “Illness is regarded, not as a fault in the parts but as a reaction, or mode of behaviour, or vital expression of a living unit in response to those forces which he encounters as he moves and grows in time. Cause is therefore twofold and is to be found in the nature of the individual and the nature of his environment at a particular point in time.” The environment, the totality of exterior circumstances, may be investigated by a variety of techniques physical, chemical, bacteriological, psychological and so on and in this way split up for convenience into separate components which we may call factors.