As we look at what is happening in the world around us it must surely be obvious that evil is not merely the absence of good, but an effective spiritual agent of destruction. Perhaps the greatest success of Satan is to have convinced so many people, Christians included, that he and his evil spirits do not exist. Where he has failed to do this, he has sometimes succeeded in encouraging an excessive and unhealthy interest in the activities of devils—an equally effective deceit which distracts us from the truth of the Good News of salvation won by Jesus. In this balanced and readable book, Benedict Heron deals with the difficult subject of spiritual warfare. He does this in the framework of Catholic teaching and pastoral practice, acknowledging the existence and destructive activities of Satan in their many and varied forms, whilst showing that his power is strictly limited. It is a timely and much needed book, and Catholics involved in any form of spiritual warfare will be greatly helped by its practical approach. — Charles Whitehead