Existentialism is the philosophy that places emphasis on individual existence, freedom, and choice.
Existentialism stresses the individuality of existence, and the problems that arise with said existence. Because there is so much diversity in the philosophy of existentialism, a concrete definition is hard to put down. Certain themes are common to almost all existential writing, which helps mark the writing as such. The term itself suggests one major theme, the stress on concrete, individual existence, and on subjectivity, individual freedom and choice. The idea of the highest ehthical good can be found in philosophy since the days of Socrates and Plato.