Eureka is Poe's attempt at explaining the universe, using his general proposition "Because Nothing was, therefore All Things are". In it, Poe discusses man's relationship to God and the universe or, as he offers at the beginning: "I design to speak of the Physical, Metaphysical and Mathematical - of the Material and Spiritual Universe: of its Essence, its Origin, its Creation, its Present Condition and its Destiny". In keeping with this design, Poe concludes "that space and duration are one" and that matter and spirit are made of the same essence.