Abstract
The DIS has devoted itself for over 30 years to the sociological study of data (gathered both intra and extra muros) concerning the apostolic life of male and female religious and various religious institutes, for the most part quite international in character. In the first part of the article, the authors briefly explain the sociological method the DIS has used for 35 years to study thousands of male and female religious at these institutes. Since the very beginning, these religious have been responsible for the management of the DIS as concerns technical matters. The second part of the article offers general conclusions concerning the religious life that can be drawn on the basis of the data collected. These conclusions refer particularly to the religious life in Western Europe.