A Case of Conscience

Blurb

A Case of Conscience is a science fiction novel by James Blish, first published in 1958. It is the story of a Jesuit who investigates an alien race that has no religion yet has a perfect, innate sense of morality, a situation which conflicts with Catholic teaching. The story was originally published as a novella in 1953, and later extended to novel-length, of which the first part is the original novella. The novel is the first part of Blish's thematic "After Such Knowledge" trilogy, followed by Doctor Mirabilis, Black Easter, and The Day After Judgment
The story is unusual in several respects. Few science fiction stories of the time attempted religious themes, and still fewer did this with Catholicism.
Many reacted negatively to the story, but surprisingly few educated Catholics were among them. One even sent James Blish a copy of the actual Church guidelines for dealing with extraterrestrials. These are not detailed, but merely suggest overall strategy based on whether the beings have souls or not, and if they have them, whether they are fallen like humans, or exist in a state of grace.