Didactic Oz

Didactic - 'intended to teach, particularly in having moral instruction as an ulterior motive.
e.g. "a didactic novel that set out to expose social injustice and enlighten"

synonyms: instructive, instructional, educational, educative, informative, informational, edifying, improving, preceptive, pedagogic, moralistic 
"the reforming, didactic function of philosophy"