The class system is fundamental to understanding civilization. Even though we no longer legally enforce class distinctions, they are thoroughly engrained into our culture. For example, the division between management and labor is nearly as sharp as that between nobles and serfs, or between officers and enlisted men in the military. These distinctions are not based on functionality, but on tradition.
Government as we know it came into existence when a band of nomadic raiders decided to settle down and collect taxes. With few exceptions, governments are created by conquering armies, who then set themselves up as a ruling class. The primary function of government is the systematic subjugation and exploitation of a conquered society for the benefit of the conquerors and their posterity. Essentially, it is a form of organized crime.
The class system is not based on any sort of "social contract," but rather is imposed on society by violence. Setting up a class system for the first time always results in a blood bath. Once a society has been "domesticated," however, replacing one ruling class with another becomes relatively easy.
Rulers are ethnically, culturally, and often racially distinct from the ruled. The origins of ruling classes were nomadic herding societies, and their culture still reflects this. In particular, fighting, thieving, art and religion are far more prevalent in herding and hunting societies than in agrarian societies.
In Systems of Survival Jane Jacobs developed a list of the distinct ethical and moral beliefs of the two classes:
Noble ValuesShun trading.
Be obedient and disciplined.
Adhere to tradition.
Deceive for the sake of the task.
Make rich use of leisure.
Common ValuesShun force.
Dissent for the sake of the task.
Be open to inventiveness and novelty.
Come to voluntary agreements.
Invest for productive purposes.
Collaborate easily with strangers and aliens.
Promote comfort and convenience.
Use initiative and enterprise.
Of course, the defining and most obnoxious tenet of a hereditary class system is that no amount of talent, no service to the realm, nor any accomplishment by a commoner can ever make him equal in status to the nobly born. A classic example of this is a Prussian practice where a ceremony was held after each war where the King personally thanked every (noble) officer for his service, and shunned any commoner who received a battlefield promotion (after which he was stricken of his rank).
See also The State by Franz Oppenheimer and Freedom and Domination by Alexander Rustow.
We may not be aware of it, but class values permeate our lives.
When peasants toiled in the fields, fair skin was considered the ideal. When workers began to toil in mines and factories fron dawn to dusk, tanned skin became the mark of beauty.
Women's clothes have buttons on the "wrong" side in order to make it easier to be dressed by a servant. Women who were not dressed by servants still put buttons on the wrong side in order to make it seem as if they were, or simply in slavish imitation of ruling class fashion. Today hardly anyone is dressed by a servant, but we still put buttons on the wrong side of women's clothes.
Men's fashions still imitate the clothes of Prince Albert, including his habit of leaving certain buttons un-buttoned.
Drama and Tragedy are part of the ruling class cultural heritage, while comedy (from the Greek word for the market) comes from common class culture. This might explain why comedies rarely win Oscars.