W.N.P. Barbellion's The Journal of a Disappointed Man is the diary of a young naturalist dying of multiple sclerosis, written with such wit and vitality that it became a literary sensation when published in 1919. Barbellion, a pseudonym for Bruce Frederick Cummings, was a promising scientist at the Natural History Museum in London whose ambitions were progressively curtailed by illness. The journal records his love of nature, his reading, his relationships, and his struggle to come to terms with mortality. Barbellion writes with brutal honesty about his physical deterioration and his emotional responses, which range from despair to defiance. The style is elliptical and aphoristic; entries leap from scientific observation to philosophical reflection to self-lacerating confession. Despite its subject, the journal is not depressing; Barbellion's intelligence and humor illuminate every page. H.G. Wells wrote the introduction, and the book has been admired by readers from Virginia Woolf to contemporary writers. This edition includes A Last Diary, the posthumous sequel. The Journal of a Disappointed Man is a unique document, neither clinical case study nor sentimental memoir, but something rarer: an unflinching account of what it means to be mortal. Essential reading for anyone interested in life-writing or the literature of illness.