Peter Senge, founder of the Center for Organizational Learning at MIT's Sloan School of Management, experienced an epiphany while meditating one morning back in the fall of 1987. That was the day he first saw the possibilities of a "learning organization" that used "systems thinking" as the primary tenet of a revolutionary management philosophy. He advanced the concept into this primer, originally released in 1990, written for those interested in integrating his philosophy into their corporate culture. The Fifth Discipline has turned many readers into true believers; it remains the ideal introduction to Senge's carefully integrated corporate framework, which is structured around "personal mastery," "mental models," "shared vision," and "team learning." Using ideas that originate in fields from science to spirituality, Senge explains why the learning organization matters, provides an unvarnished summary of his management principals, offers some basic tools for practicing it, and shows what it's like to operate under this system. The book's concepts remain stimulating and relevant as ever. --Howard Rothman