by
[review]
[excerpt]
[endlinks]
[purchase]
Reviewed by
|
|
|
Review
The discovery of the cause and cure of disease is far from a purely rational process. Human maladies cannot be processed routinely using standard laboratory operating procedures or debated away in scientific symposia. That does not mean, of course, that medicine can be explained entirely in terms of the underlying psychological or social factors that influence its researchers.
Author Paul Thagard, professor of philosophy and director of the Cognitive Science Program at the University of Waterloo in Canada, would doubtless include the role of serendipity in research, the cohesive nature of science as a group activity, and the increasing importance of emerging technologies such as the Internet in any attempt to explain how medicine advances today.
His new book, How Scientists Explain Disease, is a detailed and wide-ranging examination of the nature of medical science. It is a multifaceted, impressive work encompassing medical history, the philosophy of science, analysis of human cognitive processes, and the crafting of a cutting-edge analogy for understanding the work of the research communities. To illustrate and unify his thoughts on disease detection and treatment, Thagard focuses on a particularly interesting and, for his purposes, appropriate recent triumph of medical science.
In 1983, Australian scientists Robin Warren and Barry Marshall published a paper that advanced the theory that a species of spiral bacteria caused peptic ulcers. Originally called Campylobacter pylori, this new species was eventually named Helicobacter pylori. Warren and Marshall's discovery of H. pylori, and its proposed treatment with antibiotics, called into question the long-held assumption that bacteria could not survive in the human stomach because of its acidity. Everyone "knew," of course, that ulcers were caused by excess acidity, commonly associated with stress and the use of nonsteroidal anti-inflammatory agents such as aspirin. Thus, a classic case of innovative theory versus the dogma of the scientific establishment developed as Warren and Marshall tried to prove their case.
Step by step, Thagard shows how Warren, Marshall, and other colleagues, such as the American researcher David Graham, were able to prove that H. pylori infection causes gastritis and peptic ulcers. Their efforts exemplify the process of conceptual change throughout the medical sciences. While stressing the importance of dedicated laboratory teamwork and the skillful use of sophisticated tools such as the electron microscope, Thagard is careful to note that scientific breakthroughs do not always follow the same path.
In the case of H. pylori, Warren and Marshall satisfied two of the famous postulates of Robert Koch, the 19th-century German pioneer of microbiology. They showed that the parasite was constantly present in the diseased area, and they isolated and grew a sample of it in a pure culture. The third postulate, concerning the ability of the pure culture to induce the disease in an experimental host, was dramatically demonstrated for gastritis when Marshall swallowed an H. pylori culture and soon developed that ailment.
This important postulate could not be satisfied, however, when it came to proving that H. pylori caused peptic ulcers. Not every person who is infected with H. pylori develops ulcers. However, confirmation of Warren and Marshall's theory followed the successful treatment of test patients suffering from H. pylori infection and peptic ulcers with the antibiotic tinidazole, which eliminated the bacteria.
By 1995, acceptance of H. pylori as a leading cause of peptic ulcers had become widespread throughout the Western medical establishment. Compared with the centuries-long debate over the cause of scurvy - which Thagard analyzes by way of contrast - the decade and a half spent evaluating Warren and Marshall's theory represented a swift and resounding success.
Thagard's book, however, hardly rings with a note of celebration. One of his aims, indeed, is to use the case history of H. pylori's link to peptic ulcers to rebut iconoclastic critics of medical science. Their contentions that the scientific process is one of "self-vindication" or "just another semiotic exercise like literary criticism or fashion design" present, in the author's view, a cause for concern. Under the guise of pragmatism, one critic quoted in the book propounds that "truth and knowledge are relative matters, malleable and dynamic."
Thagard skillfully deflates such "antirealism." Among his trenchant arguments is the observation that it was rigorous tests and challenges by skeptics of the H. pylori theory that helped confirm its validity. For those who continue to believe that "H. pylori and the diseases it causes are pure social or mental constructions," Thagard suggests that they swallow a bacterial culture, as Marshall did, in order to get a taste of reality!
The author's convictions are even more evident in his book's concluding pages. Defending scientific methodology, Thagard unequivocally states that "since the emergence of modern empirical science around the sixteenth century, no other mode of thinking or acting has even approximated science's ability to generate theoretical understanding and practical applications."
This determined effort to defend science, however, is somewhat hampered by the book's format. It begins with an involved study of disease schemas and comparisons of cognitive and social approaches to science. The fascinating H. pylori case study at its core is discussed with great insight and ability. Unfortunately, Thagard's book often requires considerable effort to read. This is not to say that he is a poor writer, for his prose is generally quite lucid. Rather, the proliferation of diagrams, the repetition of salient facts, and the seemingly endless references to supporting texts inhibits the book's narrative flow.
It is unfortunate that Thagard did not begin with a dramatic presentation of the H. pylori saga and then discuss his more detailed material in a second section or in appendices. This would have enhanced the audience appeal of his book, which indeed deserves to be widely read.
Despite this organizational caveat, How Scientists Explain Disease is a book that amply rewards the dedicated reader. Thagard is certainly one of the first science writers to cogently discuss the implications of the Internet. He skillfully demonstrates through his case study of H. pylori how scientific consensus is reached on a wide scale. Perhaps most importantly, in championing the cause of dedicated teamwork throughout the medical science community, Thagard presents a powerful image of an interacting realm of "mind, society, and world."
Ed Voves is a news researcher for Philadelphia Newspapers Inc., publishers of the Philadelphia Inquirer and Daily News. For the past twelve years, he has written book reviews, author interviews, and other news articles for both papers.
It is impressive that, despite . . . difficulties in determining the causes of diseases, modern medicine has made remarkable progress. It took more than three hundred years to identify vitamin C deficiency as the crucial factor in scurvy, and sixty years to identify prions as the cause of Creutzfeldt-Jakob disease. Strikingly, the period from the characterization of AIDS to the identification of HIV as the plausible cause of AIDS was only three years.
You may purchase this book (268 pp., hardcover) directly from:
Helicobacter pylori and Ulcers: a Paradigm Revised - an illustrated, well-written recent article on the H. pylori story. Published by the Federation of American Societies for Experimental Biology.
Helicobacter pylori in Peptic Ulcer Disease - an important NIH report described in Thagard's book, and a prime example of how consensus is reached in the scientific community.
Helicobacter Foundation - founded by Barry J. Marshall, codiscoverer of H. pylori's role in ulcer genesis, in 1994. The foundation maintains a well-illustrated Web site that provides detailed information about the bacterium, the rate of its prevalence throughout the world, and treatment methods.
European Helicobacter pylori Study Group - an interesting example of the cooperative efforts of the medical science community, one of the major themes of Thagard's book.
Helicobacter pylori and Peptic Ulcers - a detailed study of H. pylori from the British journal Bandolier.
Medical History on the Internet - a list of links and resources.
The Natural History of Infectious Disease - an essay by Robert DeSalle. Part of the site Epidemic! A Fred Friendly Seminar. Sponsored by the Public Broadcasting Corporation and the American Museum of Natural History in New York City.
