This document provides an overview of existentialism and its key themes. It discusses how existentialism emphasizes individual existence, freedom and responsibility in determining one's own meaning in life. Some main concepts covered include the absurd, facticity, authenticity, angst/dread, despair, and opposition to rationalism. Existential psychotherapy is also mentioned as operating on the belief that inner conflict arises from confronting the givens of existence like death, freedom, and isolation.