Physicists actively engaged in advanced research should be en couraged to discuss results and deepen their theoretical understand ing of the data. It is practically impossible nowadays to achieve the goal of the old times when small groups of scientists had the privilege of debating their ideas and the details of their experi ments in an informal and friendly way. Conferences are now too wide in scientific coverage and, in consequence, there are often too many participants. The Highly Specialized Seminars of the Ettore Majorana Centre for Scientific Culture are intended to provide such a...