Mentats of Dune by Brian Herbert

Mentats of Dune : Paperback : Tor Books : 9780765362636 : 0765362635 : 03 Feb 2015 : The Mentats led by Gilbertus Albans, the Navigators created by Josef Venport, and the Sisterhood rebuilt by Mother Superior Raquella all strive to improve the human race, but each group knows that as Butlerian fanaticism grows stronger, the battle will be to choose the path of humanity's future -- whether to embrace civilization, or to plunge into an endless dark age.