Can someone explain Existentialism in simple terms?

Answer 1

Existentialism is the belief that your individual subjective experiences are what is important, have merit and have validity.

That is the bullshit answer.

Now for the real answer.

Existentialism is one of several schools of thought created by marxists. Specifically, they were created by soviet era mind control experts as part of the cold war against the US and democracy. The goal here was to deconstruct american values and change people's attitudes, philosophies and beliefs in such a way that people no longer would support democracy but would rather, support communism. This was only partially successful and resulted in a great many people in the western world becoming essentially traitors and working for the soviets against their own people. Existentialism's particular goal was to get people to stop believing in objective morality but to instead, value their own wants and desires and rationalize as good anything that feeds them. Good and evil become an opinion and morality becomes a joke. It becomes all important not to judge others, no matter how evil their behavior and unimportant to differentiate right from wrong. This is important because marxism has a great many heinously evil behaviors associated with it (most notably genocide). In order for people to accept it, you must first strip them of their religion and their ability to tell right from wrong.

Existentialism is a tool toward that end. I don't know what is worse, that many people who discuss its merits don't know this. Or that they probably do.

Answer 2

It's the idea that man is unique among creation in that man gets to define himself. A dog is just a dog. A cat is just a cat. But a human child can become all sorts of things: A priest, a pilot, an engineer, a father, a citizen, etc... All of these roles serve to define us. Existentialism looks at humanity and society from this aspect: The fact we are very maleable and have the ability to define ourselves. Jean-Paul Sartre famously put it this way: Existence precedes essence. What he meant by that is that for a human, simply being born (existence), was not the entire story. A human child will have to define him/herself throughout their lives. And only after being born will they gain an essence.