Called the "fifth-most important sociological book of the 20th century" by the International Sociological Association, this groundbreaking study of knowledge introduces the concept of "social construction" into the social sciences for the first time. In it, Berger and Luckmann reformulate the task of the sociological subdicipline that, since Max Scheler, has been known as the sociology of knowledge. "... A major breakthrough in the  sociology of knowledge." -- American  Sociological Review.