Spiritism is a spiritualistic doctrine codified in the 19th century by the French educator Allan Kardec, proposed as “the nature, origin, and destiny of spirits, and their relation with the corporeal world” (from Wikipedia.) Spiritualism is also a

belief that spirits of the dead have both the ability and the inclination to communicate with the living. What is the Spirit World and why are we here in it? (From Wikipedia )

Spiritism can be used in contexts where there is reference to principles and beliefs as defined by Allan Kardec in his doctrine. For other uses Spiritualists will be more apt.

obstinate

u00e4bstnt/ adjective obstinate refusing to change one’s opinion or selected course of action, despite attempts to persuade one to do so.

Taken from Oxford Dictionary.