VI
Both Claude Bernard and Virchow had expressed
their respective ideas before Robert Koch's discovery
of the tubercle bacillus in 1882 won the decisive vic-
tory for the germ theory of disease. Many reasons
militated against easy acceptance, one of these being
the clash with the anti-ontological tendencies of many
medical scientists. Louis Pasteur, Koch, and their fol-
lowers had demonstrated that specific microorganisms
were responsible for specific diseases. Diseases could
even be defined bacteriologically. Thus the argument
about the relationship of pulmonary consumption and
the disease in which tubercles appeared was now
solved: tuberculosis was a disease characterized by the
presence of the tubercle bacillus, just as diphtheria was
“caused” by the diphtheria bacillus; the formation of
a membrane which originally had given its name to
the disease was no more than an anatomical symptom.
Although bacteriology concerned infectious diseases
only, its influence on the general concept of disease
was great. Presumably, diseases could be bound to
definite causes; hence the knowledge of the cause was
needed to elevate a clinical entity or a syndrome to
the rank of a disease. Moreover, an infection had a
beginning and it ended after the annihilation of the
invading microbe. Between these two points in time
the person in question was sick; before and afterwards
he was healthy; consequently, health was absence of
disease. What really mattered was the invasion by the
microbe, hence the study of the microbes and of the
circumstances of their transmission appeared of pri-
mary importance. The consideration of social and
nonscientific environmental factors, which were so
important to the older sanitarians, receded into the
background (Galdston, 1940). Bacteriology and the
science of immunology, which developed in its wake,
had their home in the laboratory, where experiments
were performed on animals, sera obtained from them,
and vaccines produced out of attenuated or dead cul-
tures of bacteria and out of sera obtained from animals.
To the die-hard sanitarian this was the negation of the
holy campaign against filth; the new science did not
lead to real health, which was to be freedom from
suffering for man and beast alike (Stevenson, 1955).
Actually, of course, bacteriology was far from prov-
ing so simple in its concepts of health and disease as
at first appeared. The microorganism was not just a
demon which possessed man once it had entered. It
remained true that during epidemics some people be-
came ill, others did not. Cases became known of per-
sons harboring pathogenic microorganisms without
themselves falling ill. Obviously then, the microor-
ganism was not the sole cause; generally speaking,
bacteria were just one form of external cause of disease.
Traditionally, antecedent, predisposing causes of dis-
ease were distinguished from proximate causes, which,
under the name of aitiai prokatarktikai, the Greeks had
identified with external causes. Julius Cohnheim, an
early sponsor of Robert Koch, declared in his famous
lectures on general pathology (1877) “that the causes
of disease are not and cannot be anything else but
conditions of life or, expressed differently, they are
outside the organism itself” (p. 8). In the general field
of pathology, this paralleled what Pasteur and other
early bacteriologists claimed for infectious diseases. At
the same time, Cohnheim's argument was a logical
extension of the view of disease as life under changed
circumstances. The body's regulatory mechanisms
enabled it to function normally, i.e., as observed in the
majority of people. Disease was a deviation from the
normal process of life caused by a reciprocal action
between external conditions and the internal regulatory
abilities of the organism. It seemed logical to argue
that “the normal process of life” could be “disturbed”
only by an overpowering change in external conditions.
Cohnheim, like many others before and after him,
believed that the concept of health and disease could
be derived from a statistical definition of what was
“normal.” But statistical deviations only separate the
frequent from the rare. If disease was to be defined
as deviation from the regular, i.e., the healthy process
of life, then deviation must imply a more than statis-
tical evaluation.
Cohnheim and many physicians, then and now, un-
consciously adhered to the old biological idea of “nor-
mal” as successfully self-preserving and self-propagat-
ing, and of “abnormal” or morbid as an impediment
of, or danger to, these potentialities. Thus Virchow,
in 1885, could even go so far as to say that disease
was “life under dangerous conditions” (p. 221). From
the reductionist point of view such a definition was
hardly tenable, for what does “dangerous” mean in
physical and chemical terms? Indeed, Ricker (1951),
a German pathologist of the twentieth century, denied
that health and disease were truly scientific concepts.
They belonged to the realms of applied sciences,
“health and its preservation to that of theoretical hy-
giene, disease to that of medicine as the doctrine of
the healing of diseases.”
