Felix Louis Ortt (1866-1959), a Dutch engineer who investigated and wrote about psychic phenomena and the philosophy of occultism and Spiritualism, is probably the only individual among the list of once well-known Spiritualists from the Netherlands whose name is still recognized by people outside Spiritualism. His legendary literary output may have something to do with that but more important was his involvement with a multitude of causes we now call “alternative”. Felix Ortt was a humanitarian with every ounce of his being.
After a few years as a practicing engineer, he found his real calling in vegetarianism, animal rights, human rights, women’s rights, anti-vivisection, sexual reform to battle venereal disease, Christian anarchism and natural healing methods. In all those disciplines he took the lead, wrote brochures and books, and lived his life according to his principles.
Near the end of the 19th century, Ortt became interested in Spiritualism and dived into it with his usual enthusiasm. In 1899, his book Het Spiritisme was published. Unlike his contemporaries, he never conducted research experiments. However, he knew the international literature well and he wrote about the subject from a philosophical point of view.
In the years that followed, he wrote many books and innumerable brochures and articles for The Harmonia Brotherhood as well as about his other interests. He also found time to lecture throughout the Netherlands.
Ortt has been of enormous importance in the history of Harmonia and Dutch Spiritualism.
When he assumed the editorship of Spiritische Bladen in 1946, he was already 70 but did not retire until the year before he died. During those years (1946-1958) he transformed a rather bland magazine into an interesting one. Felix Ortt was a great man whose influence in many fields continues to this day.
For biographical information and bibliography, see entry in Dutch-language Wikipedia.
The archives of the Dutch Spiritualist Society "Harmonia" (Archive (HUA)) include records relating to Felix Ortt.
Other links to information about Felix Ortt:
http://www.answers.com/topic/felix-ortt
The preliminary biographical sketch for this entry relating to the history of Spiritualism in the Netherlands was kindly provided by Mrs. Loes Modderman in December 2013.