Eeverybody who is acquainted with the Technical Assistance Program of the United Nations knows that representatives of many professions, trained in many different countries, are working in many parts of the world. In Geneva we have growing co-operation in the field of nuclear energy in which, in a body called Euratom, we find scientists trained in many different countries working together. Why is it that engineers, doctors, biologists, physicists, and representatives of a number of other professions and scientific disciplines can work anywhere in the world? The first point I am going to make may appear a very simple and all too obvious statement: It is characteristic of all