A review by kevin_shepherd
Orphans of the Sky by Robert A. Heinlein

4.0

After decades of trans-generational/trans-galactic migration, the command structure of the starship ‘Vanguard’ has seriously devolved. With the original crew long since dead and gone, their descendants have slowly usurped science and reason, filling the widening gaps in their knowledge base with dogmatic claptrap. In this Heinlein universe the priests are now the “scientists” and subjects like math and astrophysics are heretical and blasphemous.

This is vintage Heinlein (1941). I hesitate to call it a ‘hidden gem’ because just about everything R.A.H. wrote is gem caliber and often slightly obscure; ‘under appreciated classic’ seems more applicable.