Historical Survey

As revealed by what physicians say and do, an onto­logical orientation dominates our late-twentieth- century thinking, but this was not always so. Histori­cally, the dominance of ontological and physiological thinking shifted time and again.

The Hippocratic approach was also decidedly phys­iological. Not only did the Hippocratics see the pa­tient as an integrated whole, they appreciated the need to study ailing individuals in the context of their total environment, as evidenced in Airs, Wa­ters, Places. Yet Hippocratic physicians could not escape the essential dichotomy between illness and disease. In part this was because they were superb clinical observers. They described a number of cases so faithfully that we can affix modern diagnostic names to them with certainty. At times they even gave specific names to these symptom complexes, such as pneumonia and pleurisy.

If the Hippocratics were so sensitive to the differ­ences in individual episodes of illness, how did they deal with the similarities they detected in specific syndromes to which they gave names? The answer is that they considered both, but neither to the exclu­sion of the other (Temkin 1977).

In asking why the balance seen as ideal to the Hippocratics did not become and remain the domi­nant outlook, it must be remembered that Hippo­cratic thought did not rule the Hellenistic period. Indeed, contemporaneously with developing Hippo- cratism, the nearby Cnidians, although postulating an erroneous single common pathway for disease causation, constructed a system of definite disease entities. Neither approach was entirely sufficient. As has been said, “Hippocrates did the wrong thing well; the Cnidians did the right thing badly” (Jones 1952).

As Greek culture spread first to Alexandria and then to Rome, the Hippocratic tradition was but one of many Greek schools of thought. Hippocratism is cherished today because it is more congenial to mod­ern medicine than the other competing systems of the time. In Alexandria the ontological approach was advocated by Erasistratus, who in the third century B.C. wrote books on gout, dropsy, and paralysis. In the second century A.D., Galen returned the empha­sis to the Hippocratic theme, saying in effect that a disease is not only a change in a body, but also a change in a particular body. After the decline of Rome, the Hippocratic-Galenic tradition survived in the Greek-speaking East, where it was picked up and modified by the Arabs and returned to the Latin West beginning in the eleventh and twelfth centuries.

Characteristically, however, throughout Western history, neither the physiological nor the ontological notion disappeared completely, even as one or the other was dominant. In the ninth century, Rhazes was echoing the ontological when he distinguished between measles and smallpox.

Although he never worked out a detailed system himself, Sydenham believed diseases could be classi­fied in much the same way as Linnaeus would later group plants. In an oft-quoted passage Sydenham (1848) wrote the following:

Nature, in the production of disease, is uniform and consis­tent; so much so, that for the same disease in different persons the symptoms are for the most part the same; and the selfsame phenomena that you would observe in the sickness of a Socrates you would observe in the sickness of a simpleton. Just so the universal characters of a plant are extended to every individual of the species; and who­ever... should accurately describe the colour, the taste, the smell, the figure, etc., of one single violet, would find that his description held good, there or thereabouts, for all the violets of that particular species upon the face of the earth.

To do this with any hope of accuracy, Sydenham realized that physicians must return to the Hippo­cratic seat at the bedside. Beginning in 1666 he used this method to execute detailed descriptions of small­pox, syphilis, dysentery, gout (his personal nemesis), and measles, which he differentiated from scarlatina.

Although he would later be acclaimed the “En­glish Hippocrates,” this honor is not related to his conception of disease. As noted, the Hippocratics de­scribed individual illnesses, which they perceived as unique events limited in time. Sydenham, con­versely, strove to discover syndromes that, because of their general characteristics, could be recognized when encountered in another patient. As Henry Sigerist (1971) put it, “Hippocrates wrote the histo­ries of sick persons, but Sydenham wrote the history of diseases.”

The greatest attempt to accomplish the goal of classification that Sydenham espoused came in the eighteenth century at the hands of Frangois Boissier de Sauvages when he published Nosologixi metho­dica, in which diseases were divided into 10 classes, 40 orders, and so on, to 2,400 species (Sauvages 1768). For the most part he was unwittingly describ­ing symptoms and syndromes, not disease entities. Yet the idea was widely emulated. It appealed to clinicians, who had only to classify their patients’ conditions correctly: Proper treatment followed as a matter of course.

During the seventeenth century the iatromecha- nists came to the fore. This departure was led by Frangois de la Boe, also known as Sylvius, who fol­lowed van Helmonfs lead in the development of iatrochemistry and its cousin, the iatrophysics cham­pioned by Giorgio Baglivi. The details of their sys­tems need not be explored here, neither do those of the eighteenth century, the “century of medical sys­tems,” featuring the theories OfFriedrich Hoffmann, William Cullen, John Brown, and Benjamin Rush.

Though their systems were ephemeral, the ideas of these men retained one element of humoralism, which linked them to the nineteenth century. In general, they held that disease was due to an imbalance — too much or too little of something, whether stimuli, or spasm of the arteries, or nervous fluid. In the nineteenth century, disease would be defined as a deviation from the normal. Because physiological normality had a range, disease, in a sense, was a departure from the limits of range within which health was balanced. In different terms, Brown and his eighteenth-century kin, with their ideas of too much or too little, were using deviation from the normal as the definition of dis­ease.

The French clinical school of the first half of the nineteenth century exploited the investigative tool called the clinical-pathological correlation. This was the system used effectively by Giovanni Battista Morgagni a half-century earlier, which had led him to conclude that diseases originated locally in the organs of the body, and not in some imbalance of the vague fluidal humors. The process remains one of the most effective teaching devices in medicine - obtaining a detailed history and physical examina­tions, which change following the natural course of the disease, and finally submitting to the judgment of the autopsy table.

French clinicians Jean Nicolas Corvisart and Rene Laennec raised this exercise to such excellence that it became known as la methode. In the process, many diseases that had never existed by name or had been confused with others were sorted out in such a way that they could be detected in living patients. This naturally gave great impetus to onto­logical thinking.

As it turned out, however, a more forceful and effective contemporary personality belonged to the antiontologist Frangois Broussais. For Broussais, dis­ease occurred when certain structures were exces­sively stimulated. Such stimulation (irritation) pro­duced visible inflammatory lesions, which in his scheme centered in the stomach and intestines. There were then no such specific diseases as diphthe­ria and typhoid; these were considered merely varia­tions of inflammations. In part due to Broussais’s influence, between 1800 and 1880 ontology was pushed into the remote reaches of medical thinking. In his turn, Broussais would yield to the laboratory data produced by such physiologists as Frangois Magendie and Claude Bernard, and even more deci­sively to the apparently irrefutable proof that spe­cific microbes caused specific diseases.

As noted, an important conceptual emphasis of the nineteenth century was the idea of disease as devia­tion from normal. The idea existed as early as Plato’s Timaeus and, of course, was basic to the enduring humoral pathology. The word normal has a number of meanings, only two of which are germane here. The first is the notion of conforming to a type, to an ideal or an object of desire, and thus is a value judgment. The second refers to something that is usual and that can be determined by enumeration (King 1982).

The problem of normality as it confounded medi­cal practice was not a matter of accepting the defini­tions just given, but of fixing the ranges of normality and agreeing to the magnitude of departure from these ranges that should be labeled disease. The promise of a practical solution to this age-old prob­lem expanded in the nineteenth century with rap­idly developing methods of quantifying physiologi­cal functions.

As the century progressed, these methods came to include a host of chemical determinations and tools, such as the clinical thermometer, the X-ray, and a portable blood pressure apparatus. Their important common denominator was an unprecedented objec­tivity. As experience was added to these new tech­nologies, clinicians increasingly held that old and new notions of what Constitued disease must satisfy the new methods of quantification. The whole pro­cess was reinforced in the last quarter of the nine­teenth century by the establishment of the concept of specific etiology with the final vindication of the germ theory of human disease. Not only were there specific diseases, but each apparently had a specific cause. No longer was the notion of disease as devia­tion from the normal burdened by such vague and Unquantifiable etiologic agents as the four humors or nervous energy.

Now the agent responsible for the deviation from health in tuberculosis could be seen under the micro­scope. It could be recovered from human sputum grown in pure culture, injected into healthy guinea pigs, where it produced a characteristic tissue reac­tion and clinical picture, recovered from the tubercu­lous animal, grown again in pure culture, and on and on. More impressive proof that disease was real would be difficult to imagine. If not diseased, what was one to call a cavity-ridden lung from which identical pathogenic microbes could be recovered in every instance?

Social forces added to the swing back to ontology. The rise of hospital practice brought together many patients whose diseases were, for practical purposes, identical. Such devices as the ophthalmoscope and laryngoscope gave impetus to specialization, which in turn gave practitioners exposure to a large num­ber of similar clinical pictures. Out of this conflu­ence of developments, the ontological view returned at the turn of the twentieth century more powerfully than ever before (Faber 1923).

Still, as always, the concept of disease could not be reduced to black or white. New questions arose. What does one do with “Typhoid Mary” Mallon, whose gallbladder teemed with typhoid bacillus but caused Ms. Mallon no symptoms at all? The bacteri­ologist labeled this the “carrier state,” which may have comforted science, but not society. Everywhere that Mary went typhoid was sure to follow. Was she diseased? Certainly in the eyes of public health au­thorities and society. But was she ill? Not to Mary herself.

To accommodate the increasing accuracy with which late-nineteenth-century scientists could de­fine normality, practicing physicians had to reenlist an old friend, impairment, or as they called the up­dated concept, impediment. Impediment implied that, before a departure from the still-imprecise boundaries of normality could be labeled disease, a person must suffer physical or social impairment to a significant degree.

In the seventeenth century, Daniel Sennert had defined health and disease in terms of a person’s ability to perform in a natural way. In the eigh­teenth century, Hermann Boerhaave used the pres­ence or absence of impairment in a strikingly simi­lar fashion. Boerhaave also specifically anticipated one of the major problems of disease as impediment: Suffering the same objective physical deficiency, per­sons differed in their subjective perception of impair­ment (King 1982). The quadriplegic confined to a wheelchair for years would feel little impairment from an attack of polio involving his lower limbs. Yet a previously healthy person would experience para­plegia as a catastrophic impediment.

Beyond this, there were differences between what scientists considered unacceptable departures from normality and how these variations were consid­ered by patients. Enumerating blood pressure read­ings in thousands of persons led medical scientists to classify any determination above, say, 160 over 95 as the disease hypertension. The problem was that many patients with such elevations experi­enced no impediment whatever - indeed, felt per­fectly well. What was the practitioner to do in this instance? He might argue that, even if these per­sons were not impaired at the time, there was a significant probability that they would be in the future. But, again, not always. Some persons car­ried their elevations without symptoms to the age of 80 and died of unrelated causes.

Confounding all this was the question of what constituted significant impairment. The cardiac neu­rotic may be almost totally impaired by a fear of the heart attack that claimed his father and grandfather at early ages. He may refuse to get out of his easy chair even though repeated thorough medical exami­nation including sophisticated indicators of heart disease have all been negative. In practical terms, the hypertensive is diseased but not ill and the neu­rotic is ill but not diseased. Such a framework can satisfy the needs of the practitioner, but it likely leaves the philosopher unfulfilled.