Oliver Wendell Holmes MD was one of America’s best known literary figures of the 19th century. His collected works of poetry, novels, letters, essays, and medical writings fill 15 volumes.¹ His poems include the popular “Old Ironsides” (1830)² and “The Deacon’s Masterpiece”:³


 “Have you heard of the wonderful one-hoss shay
 That was built in such a logical way
 It ran a hundred years to a day.”

His essays included “The Autocrat at the Breakfast Table” (1857).⁴ He gave us the word “anesthesia” to describe the use of ether during surgery by Morton in 1846.^5,6

Graduating from Harvard College in 1829, he learned medicine in Boston and went to Paris from 1833 to 1835⁷ to study with Pierce C A Louis^8,9 who, in turn, was a student of Rene Laënnec, inventor of the stethoscope.¹⁰ Holmes’ MD degree was granted in 1836 and he opened his practice in Boston. “Holmes was not kept busy with patients, since a reputation for wit and poetry has never been known to increase a doctor’s practice.”¹¹ He taught medical students and was Dean of the Harvard Medical School from 1847 to 1853, continuing as a professor there until 1870.¹²

THE LOGIC OF MEDICINE

Holmes wrote of his education in Paris under Louis: “I have learned at least three principles … not to take authority when I can have facts, not to guess when I can know, not to think a man must take physic because he is sick”¹³ Holmes’ logic can be seen as three diagnostic choices: do nothing, test, or treat. This choice depends on the probability that the patient has the disease and the value of treatment. It depends on the accuracy of the …