This is a book of testimonials from participants to the famous Erice International Seminars on Nuclear War and Planetary Emergencies. The Erice International Seminars with their multidisciplinary scientific audiences have addressed, since 1981, a long list of planetary problems and emergencies. This book describes one of the most exciting intellectual and political ventures of the later part of the 20th century, of the decades of the Cold War, a period of bristling East-West tension with the omnipresent possibility that its management might get out of hand, and a war of unimaginable proportion and potential damage eruption. The Erice International Seminars — held in an idyllic setting of a small location in Western Sicily — were the attempt to stem these perilous tides, and to put science at the service of political problem-solving in a new, open and interdisciplinary approach aimed, at the highest scientific level. Thousands of top-level scientists, the best in their respective fields, among them many Nobel Prize laureates, have participated in the Seminars and their interdisciplinary working groups as well as the Permanent Monitoring Panels, and have helped to generate a steady and influential flow of scientific insight. United in their work in a unique community of knowledge, wisdom and shared values, these eminent scientists testify, today, the importance and the impact of the Erice International Seminars during the last 28 years.