The Professor and the Madman is a biographical film based on the book The Surgeon of Crowthorne or The Professor and the Madman by Simon Winchester.

The movie is about Professor James Murray (Mel Gibson), who became director of an Oxford University Press project in 1879, The New English Dictionary on Historical Principles (now known as the Oxford English Dictionary), and the man who became his friend and colleague, W. C. Minor (Sean Penn), a retired U. S. Army surgeon who submitted more than 10,000 entries while he was confined at Broadmoor Criminal Lunatic Asylum at Crowthorne, England.

William Chester Minor, a retired U. S. Army surgeon, suffered from the delusion that he was being pursued by a killer. During an episode in London, Minor killed an innocent stranger, George Merrett. He was tried in 1872, found not guilty because of insanity, and sent to Broadmoor Criminal Lunatic Asylum.

Doctor Brayne (Stephen Dillane) meets Minor at Broadmoor. Minor saves a guard’s life by amputating the man’s leg. Filled with guilt, Minor asks that most of his army pension be given to Eliza Merrett (Natalie Dormer), his victim’s widow. A prison guard, Muncie (Eddie Marsan), became an intermediary between Minor and Mrs. Merrett. Muncie delivers the offer Mrs. Merrett who refuses the pension. Brayne promises to protect him from his imagined pursuer, gives him room to paint, and allows him access to his library of rare books.

In Oxford, James Murray interviews for a position as editor of the Oxford English Dictionary. Murray was a self-taught scholar who left school at fourteen and had no degree. His application is criticized by some members of the Oxford University Press oversight committee is skeptical of Murray’s credentials, he is selected for the overwhelming task.

An oversight committee board member believes that “all words are valid in the language. Ancient or new, obsolete, or robust on, foreign-born or homegrown. The book must inventory every word, every nuance, every twist of etymology, and every possible illustrated citation from every English author. All of it or nothing at all.”

Murray has a solution to this intimidating assignment. He suggests that the project should enlist volunteers from everywhere English is spoken. He wrote an appeal to English-speaking people around the world and asked them to send their contributions on slips of paper. Booksellers, librarians, and newsagents distributed the request.

Muncie brings Christmas dinner to the Merretts. Finally, Eliza Merrett asks to see Minor and accepts his financial support. Minor says his life belongs to her.

Muncie and the guards give Minor a book that contains Murray’s appeal. Minor tells Brayne that he will be “all right” with this work and more books. Soon a volume of slips fills his room. Minor submits 1,000 slips to Murray and offers to take on the most elusive words, giving his address as “Crowthorne.” The slips are sent to Murray and the two men begin to correspond.

Murray makes an unexpected visit to Broadmoor. He carries a bundle of words for Minor, who Murray believes is a staff member. When Murray sees the manacles, he is not unsettled. “You are not alone—consanguineous”, he says. The word “consanguineous” means having the same lineage or origin or having a common ancestor. In this instance, I believe Murray uses the word to tell Minor that they kindred spirits and that Minor is not alone. Brayne encourages Murray’s visits.

The Professor and the Madman is an extraordinary tale of madness, genius, and the incredible obsessions of two remarkable men that led to the development of the Oxford English Dictionary.

The book was praised by the New York Times Magazine as “masterfully researched and eloquently written” and “the linguistic detective story of the decade.” the movie received poor reviews. On the review aggregator website Rotten Tomatoes, the film holds an approval rating of 43%, based 30 reviews, with an average rating of 5.50/10. On Metacritic, the film has a weighted average score of 25 out of 100, based on four critics, indicating “generally unfavorable reviews.” Nick Allen of RogerEbert.com gave the film 1½ out of 4 stars, calling it “the latest fiasco in bad movie history… the presence of Gibson and his co-star Sean Penn give the project a stuffy sanctimoniousness.” 

See the movie or read the book to learn about the history of the dictionary