This statement was drawn up by a Preparatory Commission in preparation for the Third International Congress on Mental Health which met in London from August 11th through August 21st, 1948. It is a broadly-visioned document, addressed 'to administrators, workers in the social sciences, in psychiatry, medical and allied professions, and to thinking people everywhere'. Its purpose is to stimulate and promulgate the universal application of the principles and practice of mental health with the very broadest social aims. It speaks of the vast promise which the social sciences and psychiatry hold out of reducing the toll of human waste and suffering so that we now 'stand on the threshold of a new epoch of the science of man' with immense possibilities for constructive effort. Yet we also have come to understand 'how vast destructive forces may be let loose upon the world' from distortion of human impulse on a large scale and this compels us to face the problems of better education for life with one another. Peace requires a world-wide