Existentialism is defined in "The American Heritage Dictionary of the English Dictionary" as 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 act.

2. Who are some of the leading existentialists"

Some of the leading existentialists are Soren Kierkegaard, Friedrich Nietzsche, Karl Jasper, and Gabriel Marcel.

3. How do you explain the fact that existentialism has taken so many different forms among diverse groups"

Existentialism has taken so many different forms among diverse groups because of the different ways cultural, social, lifestyle, religion, and government help form the person's opinion on how the individual should preserve himself. For example Soren Kierkegaard and Friedrick Nietzsche are two pioneers in existential philosophy. They both had similar unhappy and sour lives and were both...