Symmetry in nature

The papers published here have been written by friends, former students and colleagues of Luigi Radicati di Bronzolo on the occasion of his 70th birthday to express the affection and deep esteem he induced in them with his considerateness, intelligence, knowledge and culture. The papers appear in two volumes; on the basis of their titles it is easy to recognize that they may be grouped according to the following subjects: 1) Atomic, molecular and nuclear physics; 2) Astrophysics; 3) Elementary particles; 4) Mathematics; 5) Physical and biological ordered and disordered states; 6) Principles of quantum mechanics and of field theory.