Does bourgeoisie refers to both the middle class and the nobility?

The Bourgeoisie is traditionally used in reference to the middle class but can also be used to describe higher classes because of the perceived materialistic values and attitudes that are created as a result of their higher educated status in society. This term developed in France but has spread around the world especially as Marxism criticized the notion of the Bourgeoisie heavily. 

Social darwinism refers to the the theory that people who succeed in our economic system will one day out compete those who fail. one day the rich will out succeed the poor so we'll that there will eventually be no more poor