As key socio-cultural building blocks of human societies, institutions are distinct from organizations and, hence, are central to sociological inquiry. In recent decades, however, institutional analysis has increasingly moved toward the analysis of organizations, while treating "institutions" as the environments or fields of organizations. While the insights offered by contemporary organizational theorists have provided important keys to understanding how organizations, especially economic organizations, adapt to pressures within their environments, the authors argue that the Old Institutionalisms of functional theorizing has much to offer the New Institutionalisms. In this article, the Old Institutionalisms are revisited to construct a precise definition of institutions as well as posit a robust theory of institutional dynamics, a theory which supplements contemporary organizational analysis. Four dynamics stand out: the process of institutional autonomy, the intersection of stratification systems and institutions, modes of integration within and between institutions, and generalized symbolic media of exchange. In particular, the latter two occupy the authors' attention primarily as they have been under-theorized elsewhere.