"You, who know better than any one the motley world of cosmopolites, understand why I have confined myself to painting here only a fragment of it. That world, indeed, does not exist, it can have neither defined customs nor a general character. It is composed of exceptions and of singularities. We are so naturally creatures of custom, our continual mobility has such a need of gravitating around one fixed axis, that motives of a personal order alone can determine us upon an habitual and voluntary exile from our native land. It is so, now in the case of an artist, a person seeking for instruction and change; now in the case of a business man who desires to escape the consequences of some scandalous error; now in the case of a man of pleasure in search of new adventures; in the case of another, who cherishes prejudices from birth, it is the longing to find the "happy mean;" in the case of another, flight from distasteful memories. The life of the cosmopolite can conceal all beneath the vulgarity of its whims, from snobbery in quest of higher connections to swindling in quest of easier prey, submitting to the brilliant frivolities of the sport, the sombre intrigues of policy, or the sadness of a life which has been a failure. Such a variety of causes renders at once very attractive and almost impracticable the task of the author who takes as a model that ever-changing society so like unto itself in the exterior rites and fashions, so really, so intimately complex and composite in its fundamental elements. The writer is compelled to take from it a series of leading facts, as I have done, essaying to deduce a law which governs them."