doctrinaire
 oxford
 views  updated Jun 11 2018doc·tri·naire  / ˌdäktrəˈner/ •
adj. seeking to impose a doctrine in all circumstances without regard to practical considerations: a doctrinaire socialist.•
n. a person who seeks to impose a theory in such a way.DERIVATIVES: doc·tri·nair·ism / -ˌizəm/ n.
 The Oxford Pocket Dictionary of Current English