Book Review Letters By Oliver SacksKnopf: 752 pages, $40If you buy books linked on our site, The Times may earn a commission from Bookshop.org, whose fees support independent bookstores. There are those who can write, and those who can’t not write. Oliver Sacks fell into the latter category. A neurologist by trade, Sacks was insatiably curious and wrote ceaselessly and joyfully about anything that caught his interest, which was just about everything. Readers get a new glimpse into his mind this year, nearly a decade after his death, thanks to a handsome new collection of the doctor’s letters compiled and annotated by his longtime editor, Kate Edgar. (Knopf) To read these letters is to be reminded of the deeply felt humanism and ebullience that Sacks brought to his prose: They include condolences, replies to fans and long scientific musings that read like dry runs for his books. There isn’t a shred of cynicism or pessimism to be found here, only delight in sharing ideas and enthusiasms with friends, family, colleagues and fans. Sacks did his level best to respond to every letter that found him