Normand Berlin, Cambridge Companion (1998: 85)
This metaphysical ground is assumed to be the absence of God: O'Neill goes so far as to quote Nietzsche in Long Day and Beckett's Godot (despite the author's denial) is frequently accepted as the absent YHVH. But 'the death of God' is not simple atheism, but a recognition of the disappear of an entity that once existed but has now disappeared. And God as an absence has always been a legitimate (Christian) theology, a via negativa for the pilgrim who approaches the divine through 'the cloud of unknowing'.
Even accepting a raw atheism - a meat-hook fact believed by both playwrights and a metaphysical reality advanced by post-enlightenment secularisation - both O'Neill and Beckett describe a universe that is not so much mere materialism but defined by a lack. The absent God retains a personality, the diegetic worlds of Godot and Long Day exhibit the contours of the deity, although what was once solid is now the hollow. The characters struggle to assemble meaning - to maintain hope of redemption - using the fragments of religious scripture or childish memories of faith, yet without foundation in ontological truth, these fragments offer nothing but sound and fury, signifying nothing. This description of a reality without God conforms to a Christian notion of hell, stripped of colourful metaphor and reduced to a simple equation: life without God is hell.
A more ambitious attempt to reconfigure the godless universe can be found in Sartre's existentialism. Bad faith replaces sin, the language of theology is translated into a materialist philosophy, replacing spirit with consciousness and relocating religious ideals within the mind. O'Neill and Beckett never abandon the language of Christianity - either desperately defending the vestiges of a barely remembered Catholicism in the words of James Tyrone or the direction quotations by the tramps in Godot - and this only deepens their alienation. Far from embracing the death of God, and rising to become the ubermensch, the characters wallow in their defeat. The memory of the hope of salvation becomes another torment.
For Nietzsche the death of God was not merely a bland statement of atheism, but simultaneously a celebration of human potential and a final rejection of meaning. That he would later erect a metaphysics of eternal recurrence, a materialist afterlife that saw the perpetual repetition of existence, only emphasises the complete breakdown of meaning that this death implies. Nietzsche is compelled to invent another fiction, a system that has as little validity as the theologies that he hopes to replace. In a reality defined only by a lack of definition, only another lie can replace God.
Long Day refuses the celebrations that Nietzsche offers, and sees only the desperation of a doomed humanity. O'Neill destroys the possibility of language, depicting its ultimate inability to communicate or resolve. The dialogues between father and son, son and mother, husband and wife are merely further expressions of this inability, a satanic corruption of the Platonic dialogue (which served to discover buried meanings). Like Derrida and William Burroughs, O'Neill is deconstructing language itself, pointing out the futility of the entire philosophical project.
And yet... the via negativa, the path to God that describes only what God is not is older than Nietzsche.