If we meet an extraterrestrial who keeps shouting "gavagai!", how are we to decode its meaning? Do bees and dolphins possess a linguistic competence? Did the chimpanzees Sara, Washoe, and Nim acquire a human-like language?In this book, Premack examines our human fascination with using language as a tool to our understanding of ourselves. He clearly and wittily untangles the complex skein of arguments, put forth since Darwin's time, over whether we are unique because we can talk. Gavagai!