For his 75th birthday, friends of the writer and neurologist Oliver Sacks gave him a printout of his brain scan inscribed with well wishes. Alongside it was a mock-scientific text describing a newly identified condition: “Brilliant Bi-Hemispheric Cortical Balance syndrome.”

This “chronic condition” didn’t just enable extraordinary intellectual contributions straddling science and the arts. “Further longitudinal observations,” the text said, “suggest that his uncommon neural activation has been responsible for a supra-personal uplifting of millions of other humans who have been captivated, informed and enriched by his stories of the human brain and mind.”

Sacks’s death in 2015, at 82, prompted an outpouring from readers and admirers, who saw him as the embodiment of the kind of erudite, patient, deeply sympathetic doctor who had been squeezed out by modern medicine. Even a decade later, he remains a symbol of free-ranging, even anarchic human curiosity — if not quite as dashing as Dr. Oliver Wolf, the case-cracking, motorcycle-riding Sacks stand-in played by Zachary Quinto in the new NBC medical drama “Brilliant Minds.”

Now, the New York Public Library has acquired Sacks’s personal archive, a trove documenting his intellectual explorations of topics as diverse as “aging, amnesia, color, deafness, dreams, ferns, Freud, hallucinations, neural Darwinism, phantom limbs, photography, pre-Columbian history, swimming and twins,” to cite a partial list that once appeared on his website.

“Sacks is one of the most important humanists of the 20th and 21st century,” Julie Golia, the library’s associate director of archives, manuscripts and rare books, said.