As we have been reminded recently, humans now have the power to destroy the world. We are threatened by the nuclear storehouses in Russia and China—and our own. The nuclear arsenals of the world’s powers, we are told, could easily destroy civilization. Of course, it is now apparent that man is also cultivating viruses and diseases that could get out of control and might also wipe out civilization as we know it. Then we have the promoters of global warming that are cons...