4. _The defenders of luxury claim that it is the great incentive to progress._ It is undoubtedly true that a dead level of conditions is unfavorable to the progress of society. There must be in society some motive for emulation and ambition after the bare necessities of life are provided. There is therefore much strength in the defense of luxury. Necessities, strictly understood, are things absolutely essential to life and health. No hard line can be drawn between necessities and comforts, between comforts and luxuries. The level rises; it is a trite and true saying that the luxuries of one age become the necessities of the next. The rise of the bath-tub in the nineteenth century is an epitome of the progress of civilization in that period. The free baths in our cities surpass the hopes of the wealthy of a century ago. Even the meaner motives of envy may have their social function. The lower social grades, emulous of the higher standard held before them, labor with greater energy. The successful and capable, not content with necessities, continue to give their efforts to production. The destruction of the motive of luxury before the development of a substitute in a higher social conscience, would be paralyzing to industry. Luxury in a moderate measure may be defended by the same arguments as those for private property. True as this view may be in many cases, in others it seems directly opposed to the facts. Let us look at the economico-moral questions involved from the side of the individual who is indulging in luxury, and from that of the society in which he lives. [Sidenote: Happiness and the simple life]