My proposal, then, is that noir can also be seen as a sensibility or worldview which results from the death of God, and thus that film noir is a type of American artistic response to, or recognition of, this seismic shift in our understanding of the world. This is why Porfirio is right in pointing out the similarities between the noir sensibility and the existentialist view of life and human existence. Though they are not exactly the same thing, they are both reactions, however explicit and conscious, to the same realization of the loss of value and meaning in our lives.
Mark Conard looks at existentialism, definitions and the meaning of Film Noir, in an authorised excerpt from the book The Philosophy of Film Noir: Nietzsche and the Meaning of Noir:Movies and the ‘Death of God’.
FilmsNoir.Net 