People are sayiung class when they mean middle income range. Not the same, at all. Incomes change, but classes are usually codified into law.
This was posted by a Freeper a while ago, seems relative to our discussion and deserves to be reposted.
Time for a history lesson. Traditionally, economists, historians, and sociologists (e.g. William Lloyd Warner) divide capitalist societies into five classes:
1. The Nobility: hereditary rulers; owners of ancestral estates and properties, supported by taxation of property-owners
2. The Aristocracy: minor nobility, the clergy, the landed gentry, military officers, and peers of the realm; supported by salaries, rents and income from the state or derived from properties
3. The Bourgeoisie: the "middle class": town-dwelling commoners who support themselves by means of property through commerce and trade. Includes professionals (doctors, lawyers, etc.), small business owners, skilled tradesmen and craftsmen, artisans, artists, writers, small property owners, and civil servants.
4. The Proletariat: the "working class": people who own no property and support themselves solely by trading their labor for wages.
5. The Underclass: beggars, itenerants, petty criminals, drug dealers/smugglers, pimps, prostitutes, private soldiers and sailors, the mentally ill, the disabled, most entertainers
In the U.S. we obviously have no nobility as such; instead we have "old money" (e.g. the DuPonts) and political families (e.g. the Tafts, the Roosevelts, the Kennedys, the Bushes) whose vast networks of connections and substantial blue-chip investment portfolios enable them to operate at the top levels of power. The "aristocracy" in our society consists of those who have achieved extreme wealth and/or fame in their own right: media celebrities, tycoons, pro athletes, and the nouveau riches in every city and town. Our bougeoisie is more or less the same as in earlier times: a middle class of small business owners who make their livings by entrepreneurial activity. The working class in America consists of those who derive all their income from wages alone. And our underclass still consists of beggars, itenerants, petty criminals, drug dealers, private soldiers and sailors, the mentally ill, and the disabled. (The pimps, prostitutes, and entertainers all got promoted to the Aristocracy.)
Class is not a measure of how fine a person one is. There are plenty of noble people among the lower classes, and it's well known that scum tends to rise towards the top of any social soup. It is also not based upon one's income or net worth. Class is a status determined by how one gets their daily bread. Those who derive their income from capital (property) are either "nobility/aristocrats" (the upper class) or bourgeois (middle class). Those who derive their income from wage labor are the working class. And those who live hand-to-mouth, on the government dole, or by crime make up the lowest class. Of course, there are exceptions -- there are plenty of disabled in the middle class, and many of our soldiers and sailors are small businessmen when not on active duty -- but in very broad terms our society still has the same five-class structure it has had since the end of feudalism.