Theory | 176,693 followers on LinkedIn. Expertly-tailored pieces made from the best materials transforming the way we work and live. | Theory: Defining the New Modern Founded by Andrew Rosen in 1997, Theory revolutionized the contemporary market with its concept of the urban uniform, a modern edit of elevated essentials. The Fast Retailing acquisition of Theory in 2004 spurred global expansion of the brand; today, Theory operates 221 freestanding stores worldwide. The launch of e-commerce in 2010 and collaborative relationships with department and specialty stores continue to position Theory as a continually expanding international omnichannel phenomenon.