The Cargese Summer Institute 1975 on Weak and EZeotromagnetio Interaotions at High Energies was organized by the Universite Pierre et Marie Curie (M. LEVY et J. L. BASDEVANT)~ the KathoZieke Universiteit te Leuven (R. GASTMANS) and the Universite CathoZique de Louvain (D. SPEISER~ J. WEYERS) who made in 1973 the first oon- taots with some Zeoturers~ who~ on the advioe of NATO joined their efforts and worked in oommon. It was the 16th Summer Institute rd heZd at Cargese and the 3 one organized by the two departments of TheoreticaZ Physios at Leuven and Louvain-Za-Neuve. When the two groups decided (independentZy) on the subjeot of the sohooZ~ they oouZd not know how Zuoky their ohoioe eventuaZZy wouZd turn out to be : rareZy has it being possibZe to present an audienoe with suoh a great number of new and deoisive disooveries who are Zikely to stimuZate the imagination of theoreticians and the researoh projeots of experimentaZists aZike. Suoh were the decisive oonfirmation of the neutraZ ourrents~ the di-muon events~ the sZowZy deoaying new partioZes~ eto. The organizers were grate- JUZ indeed that they oouZd find physioists from aZmost alZ great oenters of high energy physios Who had themseZves participated in these disooveries. AZthough the theorists oouZd not matoh during the Zast two years the speotaouZar suooess of their experimentaZ ooZZeagues~ there has been enough important program~ especiaZZy in fieZd theory : renormaZization of gauge theories~ the mechanism disoovered by R. BROUT et aZ. ~ eto.