There are two types of people into whose hands this book may fall. The first is the man or woman whose nerves must not be disturbed by the spectacle of the misery of less fortunate beings: who finds life good, and instinctively resents any proposals to tamper with its foundations. These people are no more open to blame, as a rule, than the prophet is entitled to praise for his ardour. We do not choose our temperament, whatever else we choose. But one does not appeal to these comfortable people. They would have refined and pleasant things about them always, and they shrink from the vaults where, they dimly know, ugly and sordid and writhing things are crowded together: lest their glance fall on some yellow and distorted face whose hollow cheeks, or eyes bloodshot with pain or brutality, would disturb the even pleasure of their lives. So be it. Let it be written in stark letters on their marble stones, when the last peach has dropped from their relaxing fingers: My ideal was to enjoy life, and to let the devil take the hindmost. Do not let me be misunderstood. The enjoyment of life is the supreme ideal advocated in this book. I loathe asceticism, either Christian or Stoic. But I write for the second type of man or woman: the people who are strong and healthy enough to enjoy every pleasure that life affords, yet keep some thought for the unhappiness of others: who think it a normal part even of a pleasant and refined life, especially a leisured life, to spare some hours for seeking how the world may be improved for less fortunate folk: who, precisely because they love the sunlight, ask if it cannot be devised that all men and women and children shall have a larger share of it. Their chief difficulty is that, unhappily, the new prophets are as discordant as the old. A few centuries ago, when you crossed London Bridge, or the Pont Neuf at Paris, or the Ponte Vecchio at Florence, a score of rival quacks or charlatans (in the literal sense) cried in your ears the virtues of their conflicting remedies. To-day just so many conflicting social physicians cry their wares in the streets. They oppose each other almost as bitterly as they oppose the older traditions. How shall a busy man or woman decide among them? What fixed and unalterable principle, in this world of dissolving creeds, can you adopt for the testing of their truth or untruth?