Among the most famous and influential existentialist propositions is Sartre's dictum, "existence precedes essence," which is generally taken to mean that there is no pre-defined moral or spiritual essence to humanity except that which we make for ourselves. Human beings are not pre-determined in any way but are free to do as they choose - they must be judged by their actions rather than by 'what they are', since they 'are' entirely what they do. This version of existentialism does not admit the existence of a god or of any other determining principle. Sartre also warned against all 'viscous' elements of existence, that might ensnare the freedom that is the human being. As long as the traps of viscosity can be avoided, the main problem for the human being then becomes that of how to choose one's actions.
Soren Kierkegaard, a 19th Century precursor to 20th Century existentialism, discussed this challenge in his writings on angst. Others, such as Karl Jaspers[?] and Gabriel Marcel[?] pursued more theological versions of existentialism.
The main tenets of the movement are set out in Sartre's L'Existentialisme est un humanisme, translated as Existentialism and Humanism.
See philosophy for a list of other concepts related to existentialism.
Novelists and Playwrights:
Modern music dealing with existential topics: