Oliver Sacks, one of the great humanists of our age - who describes himself in these pages as a 'philosophical physician' and an 'astronomer of the inward' - wrote to an eclectic array of family and friends. Most were scientists, artists, and writers, even statesmen: Francis Crick, Antonio Damasio, Jane Goodall, W. H. Auden, Susan Sontag, Stephen Jay Gould, Björk, and his first cousin, Abba Eban. But many of the most eloquent letters in this collection are addressed to the ordinary people who wrote to him with their odd symptoms and questions, to whom he responds with a sense of generosity and wonder.

With some correspondents, Sacks shares his struggle for recognition and acceptance both as a physician and as a gay man, providing intimate accounts as well of his passions for competitive weightlifting, motorcycles, botany, and music. With others, he chronicles his penchant for testing the boundaries of authority, the discovery of his writer's voice, and his explosive seasons of discovery with the patients who populate his book Awakenings.

His descriptions of travels as a young man and the extraordinary people he encounters can be lyrical, ferocious, penetrating and hilarious. Many of his musings include the first detailed sketches of an essay forming in his mind, or miniature case histories rivalling those in his beloved essay collections.

Sensitively selected and introduced by Kate Edgar, Sacks's longtime editor, the letters trace the arc of a remarkable life and reveal an often surprising portrait of Sacks as he wrestles with the workings of his own brain and mind.