Human uses of mammals that "one is well advised to study the behaviour rather than attempting to get at any underlying emotion". Charles Darwin however had accepted the idea of emotion in animals, writing his 1872 book "The Expression of the Emotions in Man and Animals" on the subject. Darwin believed that mammals had social, mental and moral lives. In "The Descent of Man" (1871), he wrote: "There is no fundamental difference between man and the higher mammals in their mental faculties." Biologists remained wary of the idea, even for the great apes, but this led to serious difficulties, as Donald O. Hebb explained
The Man in the Moone as one of the first works of science fiction, there is no general agreement that it is even "proto-science-fiction". Early commentators recognised that the book is a kind of picaresque novel, and comparisons with "Don Quixote" were being made as early as 1638. In structure as well as content "The Man in the Moone" somewhat resembles the anonymous Spanish novella "Lazarillo de Tormes" (1554); both books begin with a genealogy and start out in Salamanca, featuring a man who travels from master to master seeking his fortune. But most critics agree that the picaresque mode is not sustained throughout, and