Complex sentence: Although the book is set in the fictional kingdom of Glome, Greece is often invoked to give the story a setting in time, as well as to allow for an interplay between the Hellenistic, rationalistic world-view and the powerful, irrational, primitive one.
Split into simpler sentences: Although the book is set in the fictional kingdom of Glome, Greece is often mentioned. In effect, the story deals with the interplay between the Hellenistic, rationalistic world-view and the powerful, irrational, primitive one.