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A Vital Science1

A Vital Science1

A VITAL SCIENCE1

-Jack R. Holt

A DISCUSSION Throw theory into the fire; it only spoils . -Mikhail Bakunin, 1842

Some years ago I was asked to lead a faculty discussion about a book dealing with a biological subject. Silly me. I thought that the exchange would be fairly cursory, and that I would end up answering questions about biology. Instead, after an initial discussion and explanation of terms, several who objected to the book and its message because it was reductionist assailed me. This response took me by surprise because I had heard about this view and studied it in a course on the . I was intrigued to hear such anachronisms. I would have assumed that the whole exchange was tongue-in-cheek, except that the vocal participants were so passionate. Then, one of them (who retired from the university not long afterwards) in a patronizing tone advised me that I would never understand the real mystery of life until I adopted a more holistic view and rejected the notion that biology could be reduced to and physics. The theory that my antagonist defended was called vitalism. Since the time of , it was believed that life and non-life were fundamentally different. They were so different that (1660-1734) declared that living things were not governed by physical laws but by laws or principles that are unique to life and the products of life. Adding heat could destroy the vital force. For example, a living branch of a tree could have its vital force removed by burning and its products (carbon dioxide, water, etc.) rendered non-living. This separation is still apparent in the division of Organic and . The concept of vitalism persisted in the science of biology and well into the 19th century.

WHEN IS IT SCIENCE? All this made me feel that, to everyone of the main problems, I had better answers – more coherent answers - than they had. - Philosopher of Science Sir Karl Popper (1902-1994; see Figure 1) struggled with the question of science and what separates science from . He recognized that pseudoscience could sometimes be right and that science could be in error. What makes theory scientific? He cast about for a measure and found it in the way in which the theory was presented and explained phenomena. In particular, Popper rejected the idea that scientific theories could be proven or even verified. He said what makes a theory scientifically valid is that it can be shown false or falsified. This, he thought was the fundamental attribute of science and that which separated science from pseudoscience. Consider the rival theories of vitalism and in the 18th century and evaluate them them with Popper’s falsification requirement. The Mechanist theory was a view that there was no fundamental difference between life and non-life and that all of existed on a continuum from inorganic to organic. A prediction of the mechanists was

1 This is a revision of an essay that I wrote in 1998 and published in a collection called Paths of Science in 2001.

1 that of life should occur often. The microscope had been invented and very tiny things were observed in drops of water and scrapings from teeth. Surely, things as simple as these could appear spontaneously. We all see this spontaneous generation as bread goes moldy and forgotten soup in the refrigerator turns cloudy and begins to stink as it teems with bacteria.

FIGURE 1. Sir Karl Popper

The Vitalist prediction was that the mold and microbes appeared only because they came from spores that fell from the or were not killed by the boiling. That is, spontaneous generation was not possible. Experiments had been performed in which beef or mutton broth were boiled and then sealed. John Needham (1713-1781) performed the first such experiment or test of the Vitalist theory. He boiled meat broth, sealed it, and the sealed broth began to turn cloudy. He used this as a confirmation of spontaneous generation. An Italian named Lazarro Spallanzani (1729-1799) objected and said that Needham did not boil the broth long enough. Spallanzani repeated the experiment but boiled the broth for nearly 2 hours before he sealed the flasks. This time, the broth did not become cloudy. Mechanists like Needham said that Spallanzani boiled the flask so long that he destroyed the vital principle in the air and so spontaneous generation could not occur. Needham’s objection seemed almost vitalistic. In Popper’s view, the Mechanist theory could be scientific, but its proponents did not set clear boundaries to demonstrate that they were false. The theory seemed to be true regardless of the outcomes. So, it failed Popper’s most important test. All scientific theories must be falsifiable.

NORMAL OR REVOLUTIONARY? A is usually felt to be better than its predecessors not only in the sense that it is a better instrument for discovering and solving puzzles but also because it is somehow a better representation of what nature is really like. -Thomas S. Kuhn (1970)

In a mild rebuttal to this idea, another philosopher of science named (1922-1996; see Figure 2) said that scientists work to confirm their theories, not to disprove them. In it runs counter to human nature to expect otherwise. He describes normal science as an activity of puzzle-solving. In this, scientists accumulate data and

2 information as it is important within the context of a major theory or . Vitalism is an example of such a paradigm.

FIGURE 2. Thomas S. Kuhn

Sometimes, in the period of normal science, rival will arise (as in our example of mechanism vs. vitalism). Scientists then choose the paradigm that helps to better explain the phenomena explored by the theory. Scientists like Einstein, Newton, Darwin, and Mendel were revolutionaries. The hundreds of contemporary scientists who worked in the normal science mode as puzzle-solvers are much less well known. Revolutionaries make a better story. As in political revolutions, scientific revolutionaries sometimes end as intellectual martyrs. Such was the case of Ignaz Semmelweis (1818-1865; see Figure 3), a Hungarian born who came to the hospital of Vienna as a trainee in the obstetrics ward from 1844-1848. The hospital had two different birthing wards. The First Maternity Ward was staffed by and the Second Ward by midwives. That said, he was disturbed by the disparity in rate between the two wards. Women in The First Ward suffered a death rate of 6.8-11.2% due to an infection called Childbed Fever. The Second Ward had a death rate of only 2-2.5% in the same period. It seemed to Semmelweis that the cause for this could be found and treated. Also, he was certain that the problem represented a difference in the two wards. So, he set about trying a long list of tests. He tried having women deliver on their sides. He changed the route that the priest walked as he went to give last rites to a dying patient (in case the presence of the priest scared the women to death). He was nearly ready to give up when he went to Venice for a vacation to clear his head and attempt to think through the problem. Upon his return to Venice, he learned that the head of Forensic Surgery named Kolletschka had died of all the symptoms of Childbed Fever. This had come on him after he cut himself with a knife during an autopsy. Semmelweis reasoned that Kolletschka had introduced cadaverous (dead) tissue into his bloodstream thereby transmitting the disease to him. Similarly, women in the First Ward were attended to by medical interns who had spent the morning dissecting cadavers. If they carried any "cadaverous" material on their hands or under fingernails, they could transmit the disease to women who had given birth. In 1847, Ignaz Semmelweis instituted a policy of thoroughly washing hands before seeing patients in the First Ward. Quickly, the death rate dropped from more than 12% to less than 2% in the same year.

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FIGURE 3. Ignaz Semmelweis

Semmelweis had pursued a puzzle and solved it. Indeed, he seemed almost revolutionary. However, the physicians were not impressed. By 1848 he was expelled from the hospital, and he finally ended his days in an Insane Assylum where he died. The cause of his death was somewhat mysterious and he may have been the victim of murder. Why didn’t medicine follow his lead? Mainly because the "theory" of Semmelweis did not explain anything. He made certain changes and the death rate dropped. What was the connection? How could the transmission of cadaverous material cause disease?

GERM THEORY An investigator with the standard medical view in mind, let alone one with a brain swept clean of all pre-hypotheses, could never have developed the whole concept of infecting microbes from the small evidence with which Pasteur began. -David Bodanis (1988)

Louis Pasteur (1822-1895; see Figure 4) had an undistinguished career as a student and received his Ph.D. in Chemistry in 1847, the same year as Semmelweis’ discovery. He had a short temper with a somewhat arrogant air about him. Still, he was a genius at cranking out ideas. Through the 1850’s he began to work on . Also, during this time he finally laid to rest the concept of spontaneous generation by a set of brilliantly conceived demonstrations that built on the work of Spallanzani. Rather than seal the flasks, Pasteur drew out the neck into a graceful s-shaped neck. This allowed air to enter the flask (countering Needham’s objection) and still trapped air-borne microbes. Some of Pasteur’s flasks from these experiments can be seen to this day at the Pasteur Institute in Paris (Figure 5). He began to work on wine and its fermentation by yeast. He watched the yeasts through the microscope until he was convinced that they were alive and therefore, the agents that caused grape juice to ferment to wine. While studying wine, he noticed that

4 bad wine contained yeasts and smaller microbes called bacteria. He reasoned that the bacteria were ruining the wine and devised a method to kill the unwanted microbes. He advised the wineries to heat the wine gently. (Today, this process is called Pasteurization). He began to work on diseases of silkworms and then tackled the beer industry (mainly because he hated the Germans and wanted French beer to be better than that of the Germans).

FIGURE 4. LouisPasteur.

FIGURE 5. One of Pasteur’s original flasks now in the Pasteur Instutute in Paris.

In 1868 he suffered a stroke that left his right leg partially paralyzed. Still, he did not stop or slow down for that matter. He began to work on disease and ways of curing it. His work with fermentation and the silkworms caused him to consider that disease might be the result of microbial fermentation in a living body. This was the beginning of the idea that we now call the Germ Theory of Disease. That is, living microbial agents cause particular diseases; they are not simply symptoms of disease.

5 During this time, Pasteur began to work on Chicken Cholera and then on Anthrax. He followed the research of Edward Jenner (1749-1843) who had pioneered the use of inoculation to immunize against small pox. Pasteur grew a weakened form of the chicken cholera and gave it to his chickens. He followed that with murderous doses of lethal bacteria and the chickens survived. Pasteur applied his same method to immunizing sheep and cows against anthrax, a disease that caused large losses of livestock in France and could be transmitted to humans. He announced that he would make a vaccine that would protect livestock against the disease. Although his accomplishments were great, this boast brought the ridicule of the medical and veterinary communities. In a fit of anger, Pasteur challenged his detractors. He said that he would immunize 24 sheep with his anthrax vaccine and then inoculate 48 sheep with anthrax. With great fanfare and showmanship, Pasteur inoculated the sheep and then on May 31, 1881, he inoculated all of the animals with the deadly form of anthrax. On the afternoon of June 2, all of the protected sheep were healthy while all of the unprotected sheep were dead or dying. Those who reported that day said that it was like a conversion experience. Some of those who scoffed the loudest before the demonstration asked Pasteur to immunize them against anthrax.

A RELUCTANT PHYSICIAN Koch’s genius in these experiments [with anthrax] lay in the simple and yet extremely effective technique that he worked out; indeed, it was in this sphere that he afterwards won his greatest successes. -Erik Nordenskiold (1928)

Robert Koch (1843-1910; see Figure 6) was a German physician who had become interested in anthrax. He worked carefully and persistently through the 1870’s on a particularly vexing problem with the disease. Why did certain fields seem to have the specter of anthrax about them? The aspect that seemed so puzzling was that the anthrax organisms, although deadly, were quite delicate and easily killed outside the bodies of animals. How could such delicate microbes live in a field until livestock are introduced? Koch was extraordinarily patient and careful in his research (although he tended to neglect his medical practice). He devised a method to grow the microbes in a drop of fluid from a cow’s eye with a tiny piece of infected spleen. Then, he set about to carefully prove that the anthrax bacillus caused the disease. For this proof, Koch applied four postulates: 1. Find the microbe in an organism that shows symptoms of the disease. 2. Isolate and grow the microbe outside of the organism. 3. Infect another organism with the isolated microbe. The microbe should elicit the same disease symptoms. 4. Isolate the microbe from the organism and check to see that it is the same one. By application of these postulates, Koch sought to provide a general method by which anthrax or any other agent of disease could be examined. He was concerned that others like Pasteur were too sloppy in their methods and thinking and needed to adopt more rigorous He made careful microscopic of the Bacillus that caused anthrax (see Figure 7 for a photomicrograph of the anthrax bacillus). Finally, one day he observed

6 dots appearing in anthrax microbes as the culture aged. He reckoned that these were spores and infected another culture with healthy spleen with them. The anthrax bacilli developed.

FIGURE 6. Robert Koch.

FIGURE 7. Light micrograph of a Bacillus culture. Note the endospores within the rod- shaped cells.

Koch and his assistants devised other methods of bacterial culture (the familiar agar plate was invented by his assistant R. Petri). He also pioneered the use of stains and microscopic photography. He also found that steam heat was most effective in killing bacteria and rendering items sterile. With his experience and methods that he developed, Koch set out to discover the causative agent of tuberculosis. It was difficult work because the microbe grows very slowly. In 1882 Koch presented his results to a very skeptical group of scientists at a meeting of the Physiological Society. He was a soft-spoken and poor speaker, so he spent

7 three days with microscopes and photographs showing them the microbe and the method by which he proved that it infected animals. He was to win the Nobel Prize in 1905 for his work on Tuberculosis. Koch went on to tackle cholera, bubonic plague, sleeping sickness, malaria, and other diseases. Pasteur conquered rabies and produced a treatment. It seemed as though vitalism had triumphed and brought the dreaded specter of disease to its knees.

A FALL OF VITALISM Even a confirmed vitalist who rejects the notion that living organisms are “nothing but” machines, will admit that progress in biological science has always depended on hypotheses formulated “as if” organisms were indeed machines. -Mordechai Gabriel and Seymour Fogel (1955)

Curiously, vitalism is no longer accepted in Biology. What led to its fall? Well, toward the end of the 19th century a crucial set of experiments began to show that life was much more complex than originally assumed. Pasteur had written that fermentation could be caused only by microbial action. However, when yeasts were killed and carefully ground up, their broken cells caused fermentation to occur in a sugar-water solution. It didn’t even require living cells. Also, the chemical components had been identified as compounds of carbon, many of which could be synthesized from inorganic substances. Where was the boundary? The past 100 years in biology has seen a complete change in direction. Now, most of the research in the biological sciences is devoted to understanding mysteries at the cellular and molecular level. Vitalism has been relegated to the history books and the quacks of science. Why did Pasteur and Koch make such an impact while Semmelweis was rejected? All three provided means to protect against disease. All had conducted the risky experiments as required by Karl Popper. All were consummate puzzle-solvers of the type described by Thomas Kuhn. However, Koch and Pasteur had provided more than a process. They led a revolution in the study and understanding of disease because they provided a theoretical framework within which to explain infection and infectious disease. So, a study that was born in vitalism is now at home within a mechanist paradigm. Disease is now explained in mechanistic terms of celluar , and immunology. The explanations of theories within biology in general can be reduced to the laws of chemistry and physics. This has become a strength of biology and a source of vigor in the sciences. Still, popular culture embraces vitalistic notions when it comes to health. Look at the number of ads that stress natural foods, vitamins, or methods of healing (I’ve always wondered what unnatural foods would be like). The underlying message is clearly outside of science and verges on the religious. Those who push such ideas as scientific claim that biology is stuck in the mechanist paradigm and needs a paradigm shift. Well, biology did consider vitalism. Its tenets were useful more than 100 years ago. Now, the explanations and predictions of vitalism are no longer useful nor consistent with the data generated by biology in this century. There may be other paradigm shifts in biology, but vitalism is dead, and biology is more vital as a consequence. -1998, revised 2003

8 Sources that I used to write the essay: Azimov, Isaac. 1964. A Short . Natural History Press. Garden City, New York. De Kruif, Paul. 1926. The Microbe Hunters. Harcourt, Brace & Co. New York. Edmonds, David and John Eidinow. 2001. Wittgenstein’s Poker. HarperCollins, Publishers. New York. Gabriel, Mordechai L. and Seymour Fogel. 1955. Great Experiments in Biology. Prentice-Hall, Inc. Englewood Cliffs, NJ. Hempel, Carl. 1966. Philosophy of Natural Science. Prentice-Hall, Inc. Englewood Cliffs, NJ. Horwich, Paul, ed. 1993. World Changes, Thomas Kuhn and the Nature of Science. A Bradford Book, MIT Press. Cambridge, MA. Kuhn, Thomas S. 1970. The Structure of Scientific Revolutions. 2nd ed. University of Chicago Press. Chicago. Kuhn, Thomas S. 1970. of Discovery or Psychology of Research? In: Lakatos, I. And A. Musgrave, eds. Criticism and the Growth of Knowledge. Cambridge University Press. Cambridge. Nordenskiold, Erik. 1928. The History of Biology, A Survey. Trans by L.B. Eyre. Tudor Publishing Co. New York. Popper, Karl. 1957. : A Personal Report. In: Mace, C.A., ed. British Philosophy in Mid-Century. Allen and Unwin. London. Popper, Karl. 1959. The Logic of Scientific Discovery. Hutchinson. London. Popper, Karl. 1963. Conjectures and Refutations. Routledge & Kegan Paul, Ltd. London. Thagard, Paul. 1997. The Concept of Disease: Structure and Change. http://cogsci.uwaterloo.ca/Articles/Pages/Concept.html Trefil, James and Robert Hazen. 1998. The Sciences, An Integrated Approach. 2nd edition. John Wiley and Sons, Inc. New York. Vallery-Radot, Rene. 1931? The Life of Pasteur. Trans by R.L. Devonshire. Garden City Publishing Co., Inc. Garden City, NY.

QUESTIONS TO THINK ABOUT 1. What does Karl Popper use as a way to determine whether or not an idea or a theory is scientific? 2. What is Vitalism? 3. What is Mechanism? 4. Why did the theories of Vitalism and Mechanism have different predictions as to the origin of life in the 19th Century? Is that true today? Why is Vitalsim no longer accepted by practicing Biologists? 5. How do Kuhn’s and Popper’s views differ as to the way science is practiced? 6. Who was Ignaz Semmelweis? How did he approach the problem at his hospital? What was his solution? How did the medical community react to his solution? 7. Who was Pasteur? What were some of the motivations for his different research programs? Pasteur said, “Chance benefits only the prepared mind.” What did he mean by that? Can you think of an example when Pasteur was prepared to benefit from a chance ?

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