Politics, philosophy, and Catholicism are the Holy Trinity of Italian cultural life, or so one gathers from practically every movie produced since the breakthrough of neo-realism in the mid-1940s. The relationship between intellectualism and passion is a distinctly Italian concern, and it propels this year's edition of New Italian Cinema, the weeklong showcase of first and second-time directors presented Nov. 12-19 by the Istituto Italiano di Cultura and the San Francisco Film Society. Michael Fox reports.