“Koch’s postulates.” These insights started with Henle, but came to full
flower with Koch.
In his careful, methodical, if not mundane, manner, Koch had delivered
his magnum opus. He detailed how he identified the organism and how he
cultured it. He concluded, “All of these facts taken together can lead to
only one conclusion. That the bacilli which are present in the tuberculosis
substances not only accompany the tuberculosis process but are the cause
of it. In the bacilli we have, therefore, the actual infective cause of
tuberculosis.”^41
In the history of science, medicine, philosophy, and mathematics, when
great proofs are published or presented, there has been a tradition of
concluding with the Latin phrase quod erat demonstrandum, abbreviated
QED, meaning “thus it has been demonstrated.” On that Berlin evening in
1882, Koch delivered perhaps the greatest QED moment in the history of
mankind. After he was finished, Koch quietly shook hands with some of
his compatriots, but faced no challenges. His assistants, later to become
famous in their own right, recalled, “I hold that evening to be the most
important experience of my scientific life,” and that Koch’s presentation
was “pure unadulterated gold.”^42
Koch was awarded the Nobel Prize in 1905 for his TB research. He
suffered humiliation and enjoyed exaltation throughout his career, at times
finding himself on the wrong side of history. His work on other diseases,
such as cholera, helped save millions of lives, and it is a shame that his
name is not as well-known as his two most important allies, whose names
are immortalized with the monikers “Listerine” and “pasteurization.”
Smooth, uniform, and rounded, little germs are microscopically
monotonous and unthreatening. While a pus-filled and fetid discharge is
revolting, up close, the little bodies swimming in the secretions are
humdrum in comportment, not resembling dragons or sea monsters. Ticks,
lice, tapeworms, and maggots are disgusting; all bacteria are tediously
mundane. Mankind has perennially been terrified of bears, sharks, tigers,
wolves, elephants, and especially humans, but the insipid world of bacteria
have always (even to this day) led to more worldwide deaths every week
than all the combined mammalian and predatory annihilations that have
ever occurred. Dreary in appearance, but ruthlessly efficient in operation,
bacteria ruled our human existence without any challenge whatsoever until