John P. Flynn, Ph.D., a professor emeritus of psychology (psychiatry) who died in 1980 after 26 years on the Yale faculty, liked to tell the story of how he acquired some neurology books at a used bookstore in New York in the early 1940s. The owner, unaware of their value, sold the rare volumes to Flynn for just $10.

The three-volume set, Textura del Sistema Nervioso del Hombre y de los Vertebrados, was written between 1897 and 1899 by the Spanish histologist Santiago Ramón y Cajal, M.D., considered the founder of modern neuroscience (this year is the centennial of the Nobel Prize in physiology or medicine to Cajal and Camillo Golgi, M.D.). John Gach, president of John Gach Books and an appraiser specializing in the neurosciences, described the set as “one of the two greatest neuroscience books of the 20th century,” along withThe Integrative Action of the Nervous System, by another Nobel laureate, Sir Charles Scott Sherrington, M.D., published in 1906. (Sherrington’s book is a compilation of the Silliman Lectures he gave at Yale in 1904, which were originally published by Yale University Press in 1906.) Cajal was the first to describe the main types of neurons as separate cells, which became the basis of the neuron theory. He also hypothesized about how neurons interact through junctions to form the circuits for brain functions. The books, purchased by Flynn in the original Spanish edition, are especially prized because Cajal himself inscribed them, with a lengthy handwritten note explaining his reasons for writing them, in 1910. “They were my father’s most prized material possession,” said Flynn’s daughter, Sarah Flynn.

Flynn came to Yale during the McCarthy era, when he was deemed a risk to national security. During the 1930s and early 1940s, his wife, Hulda Rees McGarvey Flynn, Ph.D., had been involved in an early teachers’ union and had supported the anti-fascist cause in the Spanish Civil War. After being called before the House Un-American Activities Committee in 1953, Flynn was told he could keep his job as head of the Psychology and Statistics Division at the Naval Medical Research Institute (NMRI) in Bethesda, Md., only if he divorced his wife. He chose to stay with her.

Thirteen offers of employment came from universities in the ensuing months; in all but one case the university backed out. The exception was Yale, where Flynn was hired in 1954 and worked with Paul D. MacLean, M.D. ’40, a professor of physiology and psychiatry who was studying the limbic system, and where he remained for the rest of his career. Yale’s president at the time, A. Whitney Griswold, believed strongly in academic freedom and was known for standing up to Sen. Joseph McCarthy. In a recent letter to Yale President Richard C. Levin, Sarah Flynn wrote: “My father was always very proud of being a Yale faculty member, and many are proud of Yale for taking the stand it did during this black period in our nation’s history.”

The beginning of Flynn’s interest in psychology is almost as serendipitous a tale as that of his acquisition of the Cajal volumes. In the early 1940s, while a priest in Chicago, Flynn volunteered to study psychology in order to be able to teach it. He earned a Ph.D. in experimental psychology at Columbia in 1943. A year later he left the priesthood. In 1945, while working at the PsychoAcoustics Lab at Harvard, he married McGarvey, whom he had met at Columbia and who later became an assistant professor of psychology at Yale. One year later, he went to NMRI, where he began his work in physiological psychology.

While at Yale, Flynn established the psychiatry basic science section at the Connecticut Mental Health Center and became internationally renowned for his studies on aggressive behavior and neural function. Each year the university holds a lecture in his honor.

Flynn’s legacy at Yale now also includes the Cajal volumes, which his daughter donated to the Medical Historical Library last year. In remarks read at the presentation of the set in April 2005, Gordon M. Shepherd, M.D., Ph.D., professor of neuroscience and neurobiology, said: “It will not only be an ornament in the library’s collection, but also a reminder of John Flynn’s own distinguished contribution to neuroscience at Yale, and of the generosity and thoughtfulness of Sarah Flynn in giving it a home in his memory.”