the era of this particular super­ power configuration may be waning rapidly, its place to be taken by other international arrangements not necessarily less threatening. To understand and cope with our situation we need correspondingly serious reflection. This volume forms a welcome part of that process. Un­ avoidably, a large part of our thinking about the issues of human survival must be oriented to physical and biological aspects of the total danger. But it has not escaped the authors of this book that, coupled with these aspects, there are profound psychological dangers, such as loss of the sense of futu­ rity, moral deterioration, and a fatalistic decline in the will to struggle to protect our home, the Earth.