Lumen, originally published in 1872, is the first science fiction novel to address the concept of relativity (30 years before Einstein) and to describe possible life forms on other planets.
The book is structured as five dialogues between Lumen, the spirit of a man who has recently died, and Quaerens, a young seeker of knowledge. The Q & A conversational style and Lumen’s wide-ranging, imaginative speculations bring Plato and Socrates to mind. Readers open to this didactic narrative style are rewarded with a novel of ideas that explores the frontiers of science, time travel, reincarnation and the possibility of moral evolution.
Camille Flammarion was a French astronomer and popularizer of science who wrote numerous fiction and non-fiction books. Brian Stableford’s tremendous introduction and annotations situate Lumen within the cultural and scientific heritage that preceded it, while also noting Flammarion’s influence on various science fiction writers who followed him. If you’re interested in the history of science fiction, or like your SF on the philosophical side, be sure to take a look at Lumen.