During the 1980s Ivan Illich added another dimension to his thought through the study of Medieval history. In the current volume he aims to demonstrate the extent to which the groundwork for the institutions that characterize our world today was laid in the twelfth century. The topics with which Illich engages center on health, housing, schooling, literacy, technology, peace and ethical values, his overiding concern being individual freedom realized in personal 'inter-dependence'.