THE development of methods and techniques for the release of atomic energy and the actual employment of the atomic bomb have demonstrated to the world at large, not only the immense and ever-expanding potentialities of science, but also the immediate power which lies in the hands of men of science. Hitherto the majority of those concerned with the fundamental sciences have not been directly concerned with the exercise of power but with the pursuit of knowledge. With the vast extent of their material power revealed, it now becomes both possible and imperative for them to discover the extent of their moral power and, taking their stand on ethical grounds, to indicate the full part which they are willing and able to play in human affairs and also the conditions under which they will in future agree to the conscription or hire of their minds. In order that they may do this, two things would seem necessary. First, recognizing that their work and its needs ensure for them certain privileges and that these very privileges have hitherto compelled a certain detachment from human affairs, they must more generally accept that they have other important functions as leaders in world citizenship, functions which are to-day increased in their importance by virtue of their new achievements. Secondly, they must surely, in their local, their national and their international assemblies and in the course of their teaching, consider and affirm at the earliest possible date, and frequently thereafter, what they consider to be their particular duties and their rights.