The Atomic Bomb ushered man into a new world with a bang. In this new world he has to find his bearings. Politically and economically this must be left to the practical men, whose first dazed reaction is to go on talking as if nothing has changed. Religion and morality must be more practical than that: for they are concerned with the meaning and conduct of life, and until the next development of atomic energy ushers man out this world altogether we need to know what life is about. Ronald Knox here [in God and the Atom] makes a brilliant re-statement of the old principles in a world from which so many of the old signposts have vanished.