Lithians are the extraterrestrial sentient species named in James Blish's 1958 novel A Case of Conscience. Natives of the planet Lithia, they are described as being rationalists unburdened by national identity, religion, public entertainments, sports, games, crime and parenthood. Their life cycle begins as eggs laid in the ocean, then progressing through stages comparable to that if lungfish, amphibians, arboreal reptiles and finally as mammal like reptiles.