If unity is indeed the litmus test of human progress, neither history nor Heaven will readily forgive those who choose deliberately to raise their hands against it. In trusting, people lower their defences and open themselves to others. Without doing so, there is no way in which they can commit themselves wholeheartedly to shared goals. Nothing is so devastating as suddenly to discover that, for the other party, commitments made in good faith have represented no more than an advantage gained, a means of achieving concealed objectives different from, or even inimical to, what had ostensibly been undertaken together. Such betrayal is a persistent thread in human history that found one of its earliest recorded expressions in the ancient tale of Cain’s jealousy of the brother whose faith God had chosen to confirm. If the appalling suffering endured by the earth’s peoples during the twentieth century has left a lesson, it lies in the fact that the systemic disunity, inherited from a dark past and poisoning relations in every sphere of life, could throw open the door in this age to demonic behaviour more bestial than anything the mind had dreamed possible.