Niels Bohr? Edward Teller? Werner Heisenberg? W. P. Northrup? Benjamin Stolberg? Harry M. Meacham? Eugene Kane? Anonymous?
(1) An expert is a person who has found out by his own painful experience all the mistakes that one can make in a very narrow field.
(2) An expert is someone who knows some of the worst mistakes that can be made in his subject and how to avoid them.
(3) I’ve made all the mistakes that are possible. The net result of that should be expert.
The first item has been attributed to nuclear scientist Edward Teller and Danish physicist Niels Bohr. The second item has been credited to German theoretical physicist Werner Heisenberg. Would you please explore this topic?
Reply from Quote Investigator: The earliest match for the first item known to QI appeared in “LIFE” magazine in 1954 within a profile of Edward Teller who ascribed an instance to Niels Bohr. Boldface added to excerpts by QI:[ref] 1954 September 6, LIFE, Dr. Edward Teller’s Magnificent Obsession by Robert Coughlan, Quote Page 61, Quote Page 62, Time Inc., Chicago, Illinois. (Google Books Full View) link [/ref]
But mistakes do not inhibit him. He likes to quote the dictum of Niels Bohr, the great Danish physicist, that, “An expert is a person who has found out by his own painful experience all the mistakes that one can make in a very narrow field.”
The earliest match for the second item known to QI appeared in a 1952 essay by Werner Heisenberg titled “Positivismus, Metaphysik und Religion” (“Positivism, Metaphysics and Religion”). Here is an excerpt translated into English:[ref] 1971 Copyright, Physics and Beyond: Encounters and Conversations by Werner Heisenberg, Translator: Arnold J. Pomerans, German Title: Der Teil und das Ganze, Chapter 17: Positivism, Metaphysics and Religion (1952), Quote Page 210, Harper & Row, New York. (Verified in hard copy) [/ref]
Many people will tell you that an expert is someone who knows a great deal about his subject. To this I would object that no one can ever know very much about any subject. I would much prefer the following definition: an expert is someone who knows some of the worst mistakes that can be made in his subject, and how to avoid them.
The earliest match for this general family of sayings located by QI appeared in “The Chicago Medical Recorder” in 1904 within an article by Professor of Pediatrics W. P. Northrup of New York University who had become adept at diagnosing and treating pneumonia in infants:[ref] 1904 November, The Chicago Medical Recorder, The Early Diagnosis and Treatment of Pneumonia in Infants by W. P. Northrup M.D. (Professor of Pediatrics in the New York University and Bellevue Hospital Medical College), Start Page 688, Quote Page 689, The Medical Recorder, Pub. Company, Chicago, Illinois. (Google Books Full View) link [/ref]
My one admirer kindly spoke of me, he being in an amiable mood, as an expert in this diagnosis. “Yes,” I agreed, which took him aback, “I’ve made all the mistakes that are possible.” The net result of that should be expert.
Additional detailed information about these sayings is available in the Quote Investigator article on the Medium website which is available here.
Image Note: Detail from the painting “Das Schulexamen” (“The School Exam”) by Swiss painter and illustrator Albrecht Anker circa 1862.