What are the themes in The Professor and The Madman by Simon Winchester?

One of the themes of The Professor and the Madman is the thin line between sanity and insanity. William Chester Minor, in an insane asylum for committing murder, became one of the most prolific contributors to the project that would become the Oxford English Dictionary (OED). While he suffered from what was likely schizophrenia and from paranoid delusions, he was also brilliant and had periods of great productivity. Therefore, another theme is the interconnectedness of insanity and brilliance. While combing old books for words to define, Minor showed the careful attention to detail that distinguished him among the many other volunteers that contributed to the dictionary.

Another theme is the importance of a dictionary in standardizing word use and definitions. As Winchester writes, "The language should be accorded just the same dignity and respect as those other standards that science was then also defining.” In other words, a dictionary needed to address the nuances of meanings with the precision of science. While there had been earlier dictionaries, none was yet vast enough to encompass the entire English language. The Oxford English Dictionary was the first dictionary that allowed people to use words with confidence that these words would have a precise shared meaning.

A third theme is the strange interconnections among people of different walks of life. Dr. James Murray, the lexicographer who worked on the Oxford English Dictionary for the Oxford University Press, worked with thousands of volunteers in compiling the dictionary. He had corresponded with Minor for nearly twenty years before he realized that Minor was institutionalized in an asylum. Murray was unaware that he had been corresponding with an inmate until meeting Minor--a meeting that brought together two people from very different walks of life.