Consider, then, the full measure of my sadness, reading this in-scription; not merely for Hosiah Lister, but for all of us; consider the dear cost of liberty in a world so hostile, so teeming with ene-mies and opporcunjsts, that one could not become free without casting aside all causality, all choice, all will, all identity; finding freedom only in the spacious blankness of unbeing, the wide plains of nonentity, infinite and still
This shows the theme of life, and existence, because Octavian, captured by Mr. Sharpe and now bound and masked, has nothing to do but think, so he's thinking about the conditions of all those slaves out there, including Hosiah Lister, the old slave who fought and died for the Patriots. Thought about life and his life and others lives make your mind wander, and make you feel things for others whenever it's just you and an empty room.