Unless we are all mad, there is at the back of the most bewildering business a story: and if we are all mad, there is no such thing as madness. If I set a house on fire, it is quite true that I may illuminate many other people's weaknesses as well as my own. It may be that the master of the house was burned because he was drunk: it may be that the mistress of the house was burned because she was stingy, and perished arguing about the expense of a fire-escape. It is, nevertheless, broadly true that they both were burned because I set fire to their house. That is the story of the thing. The mere facts of the story about the present European conflagration are quite as easy to tell. Before we go on to the deeper things which make this war the most sincere war of human history, it is as easy to answer the question of why England came to be in it at all, as it is to ask how a man fell down a coal-hole, or failed to keep an appointment. Facts are not the whole truth. But facts are facts, and in this case the facts are few and simple. Prussia, France, and England had all promised not to invade Belgium. Prussia proposed to invade Belgium, because it was the safest way of invading France.