In this Consciousness Classic dating from 1967, Dr. John C. Lilly details the discoveries of his research regarding the abilities of dolphins, current ideas (at that time) about their intellect, and the paradoxes of interspecies communication. The book includes a detailed account of the experiment carried out by Dr. Lilly of having a dolphin and human live together in a specially designed house, and this expanded edition includes black-and-white photo plates and additional articles and writings from Dr. Lilly on dolphins as well as other scientific subjects. This is the book that launched a subculture seeking human–dolphin interaction. Although some of Lilly’s findings on dolphin communication have now been refuted, Dr. Lilly’s willingness to delve into areas not documented in the scientific literature is still an important scientific achievement and a cultural model for younger generations.