Existentialism

definition from The American Heritage Dictionary:

n. A philosophy that emphasizes the uniqueness and isolation of the individual experience in a hostile or indifferent universe, regards human existence as unexplainable, and stresses freedom of choice and responsibility for the consequences of one's acts.

From The World Book Encyclopedia 1989

philosophical movement that developed in continental Europe during the 1800's and 1900's. The movement is called existentialism because most of its members are primarily interested in the nature of existence or being, by which they usually mean human existence. Although the philosophers generally considered to be existentialists often disagree with each other and sometimes even resent being classified together, they have been grouped together because they share many problems, interests, and ideas.
Existentialism grew out of the work of two thinkers of the 1800's: Kierkegaard, a Danish philosopher and protestant theologian, who is generally considered the founder of the movement and Nietzsche, a German philosopher. The most prominent existentialist thinkers of the 1900's include the French writers Albert Camus, Jean-Paul Sartre, and Gabriel Marcel; the German philosophers Karl Jasper's and Martin Heidegger; the Russian religious and political thinker Nicolas Berdyaev; and the Jewish philosopher Martin Buber.

Existentialism is largely a revolt against traditional European philosophy, which reached its climax in the impressive systems of Kant and Hegel. Traditional philosophers tended to consider philosophy as a science. They tried to produce principles of knowledge that would be objective, universal, and certain.
The existentialists reject the methods and ideals of science as being inappropriate for philosophy. They argue that objective, universal and certain knowledge is an unattainable ideal. Moreover, they believe this ideal has blinded philosophers to the basic features of human existence. The existentialists do not make the traditional attempt to grasp the ultimate nature of the world in abstract systems of thought. Instead, they investigate what it is like to be an individual human being living in the world.

One of my favorite courses in college; some of my favorites: The Plague by Camus and Siddhartha & Demian by Hesse. oh yea, and Metamorphosis by Kafka.