A Voyage to Arcturus (Bison Frontiers of Imagination)

Written in 1920 with all the turgid prose of the era when the author is trying to be formal and profound. It's an exploration of religion and philosophy and moral values set in a metaphorical trip to another planet.

The protagonist meets many different people with whom he debates morality, every day a new person and a new topic. Ironically he leaves several of them dead in his wake. With many he commits himself to their point of view but tomorrow changes his mind with the next interlocutor.

The end of his journey is marked by his acceptance of ultimate disillusionment.