Final answer:
The poem discussed by Gray addresses the theme of the uncertainty and instability of matter in a post-apocalyptic world, reflecting a wider discourse in literature and philosophy about changing realities and the nature of existence.
Step-by-step explanation:
Gray's poem reveals and reflects upon the uncertainty and instability that characterize the post-apocalyptic world presented in the poem. This atmosphere of uncertainty ties into the broader discourse in literature and philosophy during times of upheaval and change, where the traditional stabilities are questioned and new, often disconcerting realities emerge. Poets such as John Donne and Robinson Jeffers, along with philosophers like Jacques Derrida and Jean Baudrillard, have all contributed to this discourse, pondering the shifting nature of the world and our understanding of it. Evidence of this thematic concern can also be found in artistic works ranging from music to science fiction, all grappling with the fundamental nature of matter and existence itself, exploring the cosmological implications of these concepts, and their influence on human consciousness and creativity.