Fflaurie
May I just correct you, a Spiritualist is someone who believes in life after death, who follows the path and is totally convinced about life everlasting. It is a Medium who has the gift to give messages from beyond the grave, and to prove life exists after death as we know it. A Medium can be known as a Clairvoyant or a psychic. It is against all spiritual teachings for a Medium to predict the future, because it should not be in our hands to change the course of our destiny. So basically a Medium will give proof of an afterlife, and is a spiritualist by belief.
So a bunch of charlatans (or, to be charitable, of people who are deluded by wishful thinking) quibble over the precise categorisation of their BS (and, it seems, try to police it). Smile sweetly and pass by. Or, if you enjoy playing their variety of Dungeons and Dragons, admit that's all you're doing and don't pay too much for it.