Hektoen International

A Journal of Medical Humanities

Drs. Joseph Bell, Arthur Conan Doyle, William Osler, and the method of Zadig

Howard Fischer
Uppsala, Sweden

The whole of medicine is observation.”
– William Osler, M.D.


Paw prints. Photo by Peter Castleton on Flickr. CC BY 2.0. 

M. de Voltaire, the pen name of François-Marie Arouet (1694–1778), was an Enlightenment historian, philosopher, and writer. He opposed France’s absolute monarchy and the power of the church. He wrote 2,000 books and pamphlets, was imprisoned twice, and was once exiled to England for his opinions. His best-known work is Candide: Or Optimism (1758), a critique of events, lifestyles, and philosophers of his time.1

One year earlier, in 1757, he wrote the novella Zadig, or The Book of Fate. Zadig was a philosopher in ancient Babylonia who retired to a contemplative life after a series of successes and calamities. The name “Zadig” may come from the Hebrew tsadik, a righteous person,2 or from the Arabic saadiq, a truthful one.3

One day, as Zadig sat quietly by a stream, a royal servant searching for a runaway dog comes upon Zadig and asks him if he has seen this dog.

Zadig first asks him, “Do you mean a bitch, and not a dog?” (that is, not a male). Yes is the answer. “Is it a small dog?” Yes, again. “Did she recently have puppies? Yes. “Does she have long ears, and is lame in one leg?” Yes, and yes again. So, asks the messenger, when did you see her? “I have not,” says Zadig. How could you know so much about her if you have not seen her?

Zadig explains: “I saw tracks of a small animal in the sand, and thought it must be a dog. There were streaks in the sand between the paw prints. These were probably made by the teats of a recently delivered bitch. There were other impressions in the sand between the front paw prints—these had to have been made by long, hanging ears. Finally, the print made by one of the feet was fainter than the other three. This means that the animal was slightly lame in one leg.”

This “profound and subtle discernment,” based on naturally good powers of observation and reasoning, has become known as “the method of Zadig.”4

Dr. Joseph Bell (1837–1911) earned an M.D. degree in 1859 from the University of Edinburgh Medical School. He became a surgeon and medical school professor. He was known for brilliant diagnoses based only on observation of the patient. It was “diagnostic sorcery…born of the potent combination of minute observation and rigorous scientific method.”5 Bell describes a patient to his students:

This is a case of chronic alcoholism, gentlemen. The rubicund nose, the puffed bloated face, the bloodshot eyes, the tremulous hands, with the quick, pulsating temporal arteries, all show this. These deductions, gentlemen, must however be confirmed by absolute and concrete evidence. In this instance my diagnosis is confirmed by the fact of my seeing the neck of a whisky bottle protruding from the patient’s right hand coat pocket. Never neglect to ratify your deductions.6

Arthur Conan Doyle (1859–1930) studied medicine at Edinburgh. During his third year, he began attending Dr. Bell’s lectures. He received his medical degree in 1881. He opened a general medical practice, followed by an ophthalmology practice, but did not see enough patients to support himself and his wife. He had published stories in the past, and now turned to writing as a source of income. He thought about creating a brilliant detective. “Conan Doyle thought about his medical school lecturer, Joseph Bell. That’s what a detective should be like! He would be a detective who—just as disconcertingly as Bell—would notice the tiniest details and, with the help of his powers of observation and deduction, go on to solve the case.”7

This detective, Sherlock Holmes, first appeared in book form in 1888 in A Study in Scarlet. Conan Doyle has Holmes say, “Like all other arts, the science of deduction and analysis is one which can only be acquired by long and patient study…By a man’s finger nails, by his coat sleeve, by his boots, by his trouser knees, by the callosities of his forefinger and thumb, by his expression, by his shirt cuffs, by each of these things a man’s calling is plainly revealed.”8

Conan Doyle wrote to Bell, and also made public, that Bell was indeed the model for Sherlock Holmes.9 Although Conan Doyle stopped practicing medicine, medicine was not far from his thoughts. In the sixty Sherlock Holmes stories there are references to 68 diseases, 38 doctors, 22 drugs, and six hospitals.10

William Osler, M.D. (1849–1919), the “father of modern medicine,” received his medical degree from the McGill University Faculty of Medicine, Montreal. As a medical school professor, he practiced and taught the method of Zadig to his students,11 as did Bell.12 Osler advised his students: “Observe, record, tabulate, communicate. Use your senses…Learn to see, learn to hear, learn to feel, learn to smell, and know that by practice alone you can become expert. Medicine is learned at the bedside and not in the classroom…See, and then reason and compare and control. But see first.”

He “constantly reiterated the fact that the diagnosis of a patient’s disease often stared one in the face if one possesses a ‘seeing eye,’ has good light, and possessed proper reasoning powers.”13 Osler and Conan Doyle never met.14,15

Thomas Huxley, biologist and faithful Darwin supporter (“Darwin’s bulldog”), wrote in 1880 that the method of Zadig allows us to “conclude from an effect the pre-existence of a cause competent to produce the effect.16

The difficulty in applying the method of Zadig may be summarized by Goethe’s epigram: “What is the hardest thing of all? That which you think easiest, to see with your own eyes what is right in front of you.”17



  1. “Voltaire.” Wikipedia.
  2. “Zadig.” Wikipedia.
  3. Beth Belkin. “The art of observation: William Osler and the method of Zadig.” Annals of Internal Medicine, 116(10), 1992.
  4. Thomas Huxley. “On the method of Zadig.” Popular Science Monthly, 17, 1880.
  5. Margalit Fox. Conan Doyle for the Defense: How Sherlock Holmes’s Creator Turned Real Life Detective to Free a Man Wrongly Imprisoned for Murder. New York: Random House, 2018.
  6. Mattias Boström. From Holmes to Sherlock. New York: Mysterious Press, 2017.
  7. Boström, From Holmes.
  8. Fox, Conan Doyle.
  9. Boström, From Holmes.
  10. Harindra Karunathilake. “A ward round with Sherlock Holmes.” Journal of the Ruhuna Clinical Society, 2019. https://jrcs.sljol.info/articles/10.4038/jrcs.v24i1.61.
  11. Salvatore Mangione, Gretchen Mockler, and Brian Mandell. “The art of observation and the observation of art: Zadig in the twenty-first century.” Journal of General Internal Medicine, 33, 2018.
  12. Belkin, “Observation.”
  13. Belkin, “Observation.”
  14. Michael Bliss. William Osler: A Life in Medicine. New York: Oxford University Press, 1999.
  15. Alvin Rodin and Jack Key, eds. Conan Doyle’s Tales of Medical Humanism and Values. Malabar, FL: Krieger Publishing Company, 1992.
  16. Huxley, “On the method.”
  17. Johann von Goethe. “Xenien.” In Posthumous Papers, Weimar, 1893.



HOWARD FISCHER, MD, retired as a professor of pediatrics from Wayne State University School of Medicine, Detroit, Michigan. He spent much of his career diagnosing and treating child abuse and neglect. He has always been interested in the relationship between literature and medicine.


Spring 2023  |   Sections  |  Literary Essays

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