Robert Paul Wolff over at his website:
One must indeed have turned a deaf ear to the chatter of the public square not to have heard the constant invocation of The Middle Class. Politicians, pundits, bloggers, even economists speak of nothing else. Presidential hopefuls mouth the phrase more often than teenager girls say “like.” But a moment's reflection will reveal that “middle class” is a rather odd phrase indeed. In truth, a great deal of ideological insight into contemporary America can be achieved simply by meditating on the phrase “middle class.” It is the purpose of this blog post to initiate such a meditation.
As always, a little history is a useful propaedeutic. Old Regime France understood itself to be composed of three Estates, each with its own system of laws and courts, its own customs of dress, and its own sources of income. The First Estate was the Clergy, who owed a double allegiance, to Versailles and to Rome. The Second Estate was the Aristocracy, whose status rested on its possession of the great inherited accumulations of agricultural land. The Third Estate was the Bourgeoisie, which [originally] meant the craftsmen and merchants who lived in walled cities [orbourgs.] The members of the Third Estate were in many cases a great deal wealthier than some of the impecunious aristocrats, and the clergy, of course, controlled vast estates which, however, belonged to the Church, so the classification into Estates was in no way intended to be an indication of relative wealth. The vast majority of men and women in Old Regime France, needless to say, did not belong to any Estate. They were, one might say, beneath the law.
With the dramatic termination of the last vestiges of feudalism, the system of Estates passed into history. When Adam Smith and his followers undertook to analyze the new society emerging from feudalism, they sorted people not into Estates but into Classes according to the position they occupied in the economic organization and processes of the society.
More here.