Charles Singer's review of Influenza, edited by P. G. Crookshank was
published in the TLS of June 8, 1922.
From the earliest ages epidemics have puzzled the mind and terrified the heart
of man. That which is least understood is most feared and the pestilence
that walks in darkness has been usually more dreaded than the arrow that
flies by day. It is true that David when offered the alternative of famine,
war, or pestilence, chose the last. Yet had he possessed some of the exact
statistical knowledge of infectious disease that is accessible to us, had he
known something of the aftermath of mental and physical suffering sown by a
great epidemic, he might perhaps have chosen differently. The biblical
writer strikes a truly human note when he makes the appearance of the very
Angel of Death at the threshing floor of Araunah come as a relief to the
stricken King of Israel.
Influenza is a subject in which we have all of us, perforce, an interest.
Looked at from the point of view of the world as a whole it is, even among
great epidemic diseases, a mighty and terrible slayer. None kills so many in
so short a time, none is more dramatic, none leaves such an aftermath of
ill-health and broken lives. The outbreak of disease which coincided almost
exactly with the termination of the war is still fresh in our memories. We
watched the influenza gleaning for but a few weeks over a world in which war
had been leaping for four years, and the gleaner gathered more than the
reaper.
The very name of this plague suggests something that is unsearchable and
beyond our ken. The word comes to us from Italian and entered our language
about 1743 with the news of the great and fatal outbreak of the disease in
Rome of that year. It is nothing more than the Italian form of our word
influence, and contains embodied in itself a theory that has now passed away
of the interrelation of the parts of the world. The translators of the
authorized version make the voice from the whirlwind demand of Job “Canst
thou bind the sweet influences of the Pleiades?” The English rendering,
though philologically indefensible, represents a belief of vast antiquity
which Job himself may well have shared. It is the notion that the heavenly
bodies, which appear to move around our earth, pour down on it certain
mysterious rays which determine our actions and our fate. Astral influence,
these strange forces which flow in upon us from the stars, became very early
connected with disease; and from antiquity and throughout the Middle Ages
sickness was almost universally associated with these “starry causes.”
“Man’s body,” wrote that old quack, Dr. John Dee, “and all other Elementall
bodies, are altered, disposed, ordred . . . by the influentiall working of
the Sunne, Mone, and the other Starres and Planets.” Of mundane phenomena
epidemic outbreaks are among the most striking and most awe-inspiring and of
epidemic outbreaks influenza is, to this very day, among the most dramatic
and inexplicable. Our word influenza is nothing but the influence par
excellence.
The volume before us is an attempt to marshal our knowledge of all the
conditions associated with the outbreaks of sickness and mortality to which
the term “influenza” has become attached. It is the work of a group of
younger – and we may venture without undue indiscretion to say less orthodox
– writers. These gentlemen are linked together by a somewhat similar outlook
and by a somewhat critical attitude towards prevailing modes of medical
investigation. It is a sign of scientific health that such criticism should
be made freely, for its spirit is such as can be resented by no one who has
the advancement of knowledge at heart. The general standard of ability of
the book is a very high one, and the volume is given unity of design by its
editor who contributes seven of the seventeen essays of which it is
composed. Dr. Crookshank exhibits a philosophic grasp and dialectic power
that would mark him out among any group of writers.
Much of this volume is naturally of a highly technical nature. The general
trend of medical thought is, however, naturally and rightly of wide public
interest; and this work puts admirably for the general reader the
“epidemiological” point of view. The epidemiological standpoint is as
different and as separate from that of the medical practitioner as is
strategy from tactics or regimental regulations. We are doubtless too
accustomed to think of a disease as itself an entity, as an existence in
itself rather than as a mental concept used to cover a group of sick people
who exhibit certain phenomena in common. The confusion has been encouraged
by the great advance of bacteriology in modern times and its success in
showing that certain symptom complexes are invariably associated with
certain organisms. Yet there are dangers in confusing the mental concept of
a disease and the actual collection of cases of sick people from whom the
concept is derived. It is a point which Dr. Crookshank develops with what
some may consider almost excessive emphasis. The habit of confusing the
actual cases with an abstract conception of the disease may do comparatively
little harm in the case of certain conditions, such as malaria. which have
an essential relationship to known and controllable causes. In the case of
malaria these are, firstly, a blood parasite which is, secondly, conveyed by
the Anopheles mosquito, which, thirdly, needs landing water to breed in. It
is clear that in such a case we can completely control the distribution of
the peculiar symptoms associated with the word “malaria” if we can
completely control either parasite or mosquito or standing water. In the
case of the vast and ill-defined concourse of symptoms and of epidemic
outbreaks that are collected together wider the term “influenza” we are not
in any such happy position. It may be that here is an essential common and
controllable relationship to the complex of symptoms that we call
“influenza,” or again, it may not be. It is at least certain that we know no
such relationship. It is also certain that no one has yet been able to give
an exact definition of influenza that will “cover the phenomena.” Were such
a relationship known, were such a definition available, we might brave Dr.
Crookshank’s philosophic wrath and venture on the (philosophically
indefensible) statements that “there is influenza about,” and “Thomas Smith
has influenza.” Such statements are likely to continue owing to the
philosophical depravity of the species to which we belong. But Dr.
Crookshank is profoundly right in urging that scientific men at least must
rigidly guard themselves from the error of certain medieval scholastics who
would treat concepts as realities. That way lies confusion and mental
dishonesty; it is the path, too, of official self-satisfaction. Such
concepts, as Dr. Crookshank rightly points out, are but bills of exchange in
the counting-house of Science, which have to be cashed, discounted, or
rejected in accordance with their value at current rates at the bank of
experience. As the author admirably says:
"Just as war, revolution, and riot do not exist in nature as things, so
there is nothing with external existence or objectivity which makes its
appearance from time to time and to which we can apply the term influenza.
It is idle, therefore, to discuss whether or no the influenza of 1918-19 was
the same thing as the influenza of 1889-90. The phenomena are comparable;
but there are differences, as well as resemblances, in form, as well as in
causation."
There was recently reviewed in these-columns a work by Sir Almroth Wright in
which that doughty veteran stoutly upheld the experimental method as against
all others, assuring us that conditions controlled by experiment forms almost
the only hopeful line of advance in medical knowledge. In this volume by Dr.
Crookshank and his colleagues we have a plea for a wider use of the human
powers and tastes and faculties in the service of medicine. The
epidemiologists are making a good case against the consideration of the
laboratory as the only effective instrument of research. On the face of it
their plea is a just one, and it is certainly very eloquently put forward
here. Influenza, too, is a weak point in the armour of the laboratory
advocates, for it must be confessed that the bacteriologists have written
much and helped little on this most important topic, and, on the whole, the
epidemiologists have thrown more light than they on what is still a very
dark place. The fact is that in medicine as in other matters truth is a
jewel with many facets. It is also at the bottom of an extraordinarily deep
and dark well.
The general reader will naturally ask what, as a result of all the discussion,
do we really know about influenza? It amounts to an enormous mass of
observation linked together by a very slender thread of general ideas. About
every thirty years or so there recurs a very peculiar series of phenomena
which the editor of this volume has himself done much to elucidate. At first
there are a series of small and isolated outbreaks of acute illness. These
outbreaks are sometimes thought to be a “new” disease or “new” diseases to
which a variety of names have been attached. The conditions are not
infrequently rapidly fatal and often regarded as due to ingested poison.
These outbreaks are followed after some months by a generalized outbreak of
what is called “influenza.” The cases which go to make up the outbreak may
be and usually are protean in their manifestations, for respiratory,
nervous, gastric, rheumatic and other types have been distinguished and
peculiar local varieties have been frequently described. The generalized
outbreaks recur in a series of waves, the fatality of which varies from wave
to wave, but tends to rise steadily to a maximum fatality and then to fall
as steadily. Each wave lasts about six weeks. The waves of acute disease are
followed by other outbreaks – again localized and more sporadic – of yet
further strange types which are often mainly nervous. Most prominent among
these, at least, in the public notice, has been the “sleepy sickness”
(encephalitis lethargica). The whole cycle seems to take about five years,
and has been traced with some definiteness from the sixteenth century
onwards. The series of phenomena is most complex, and calls for further
investigation by an intensive historical study of a magnitude which is
probably beyond the powers of any one worker. Dr. Crookshank, in spite of
his preoccupations as a physician and a clinical observer, has himself
advanced some way in this direction. In this learned and able work he and
his collaborators have broken the ground for an almost new department of
epidemiological research, the organized and systematic correlation of
observed phenomena with historical data.
