Whether in Kira's struggle with the Soft Blade, the Wranaui and their reliance on replacement bodies, or the mad ramblings of fan favorite character Gregorovich, "To Sleep in a Sea of Stars" is a novel centered around ontology, particularly in its treatment of one's connection to the physical form.
Whose Kingdom is It, Anyways?
I was reading through my daily ‘Through the Bible in a Year Plan’ and this Scripture was like an anchor, not letting me surface. I had that nagging sense of déjà vu, a mild sense of uneasiness. I knew this, didn’t I? I did. All of a sudden I felt like David when the Lord confronted him through Nathan the prophet. “You are the man!” I was Nebuchadnezzar, or had been at least.
Bone of Bones 