The study of elementary particle physics and high energies, undertaken in huge laboratories such as the accelerators of Stanford, Chicago, Brookhaven, CERN at Geneva, and Dubna et Serpukhov near Moscow, is one of the most astonishing scientific feats of the last half century. The field not only allows us to understand the composition of matter and the origin and evolution of the universe, but also helps prevent these scientific instruments being used as weapons of war. The Pugwash conferences, held between scientists of the East and West, won a Nobel Prize for this very reason. Maurice Jacob, the honorary director of the division of theoretical physics at CERN, recounts in this book how these objectives have been achieved. Maurice Jacob is a theoretical physician of elementary particles.