This project makes available for the first time the entire corpus of lectures by a writer whose thought and method influenced a generation of sociologists and sociolinguists. Originally published as two volumes, this comprehensive single-volume edition contains the complete lectures, beginning with the lectures delivered at UCLA, from Fall 1964 through Spring 1968. Sacks explores a great variety of topics, but two key issues emerge: rules of conversational sequencing, and membership categorization devices. The lectures culminate in the extensive and formal explication of turn-taking delivered in Fall 1967.