Creative thinkers do not merely answer questions that interest others, they answer questions that others have not realized are interesting or even are questions.  For example:

• Starbucks coffee is not that much better than everyone else's coffee, so what is Starbucks really selling?

• What does it say about today's America that travelers changing concourses in the United terminal at Chicago's O'Hare International Airport pass beneath a 744-foot neon-light sculpture, the colors of which change in sync to music?

• Why has the number of nail salons doubled, the number of manicurists tripled and the number of cosmetic medical procedures almost quintupled in a decade? Why do 13 percent of middle-aged men spend more than $1 billion on hair coloring, up 34 percent in five years?

• If computers are just tools, why bother making them as pretty as the Sony Vaio and Apple iMac?

• How much of the booming membership in gyms is about something other than -- more pleasurable than -- health maintenance?

Virginia Postrel, an economics columnist for the New York Times who writes perceptively about everything on which her penetrating gaze alights, answers these questions, and others you may not have asked yourself, in her new book "The Substance of Style: How the Rise of Aesthetic Value is Remaking Commerce, Culture, and Consciousness." It is an appreciation of what she calls the "aesthetic imperative" in this expressive age.

Biologically we are, she says, visual, tactile beings responsive to our sensory surroundings. And we now are -- thanks to such factors as travel, education, immigration and media -- producing a society of aesthetic plenitude and pluralism.

People are eager to pay Starbucks for more than mere coffee -- for a sensory environment that pleases more than just their palates. Demand often creates supply, but supply can create demand: Travelers do not demand O'Hare's neon light sculpture, but the supply of such aesthetic amenities raises expectations for a more pleasurable environment. And from gyms and nail salons to tattoo parlors and the emporiums where people get their bodies pierced in so many interesting places, Americans are consuming design and designing themselves.