Jacques Collin de Plancy's Dictionnaire Infernal is a seminal work on demonology that has undergone numerous revisions since its first publication in 1818. The book describes in detail the various demons and their hierarchies, showing the author's transformation from skepticism to belief.
De Plancy's Dictionary of Hell is not only a chronicle of demons, but also contains a wide range of superstitious and mysterious phenomena. The book's exploration of the supernatural reveals his initial skepticism about these beliefs. His views were influenced by Voltaire, and he was somewhat skeptical of the superstitions that were prevalent at the time:
"To deny the existence of pain and reward after death is to deny the existence of God; since God exists, these must exist."
Before 1830, de Plancy's skepticism gradually changed. This transformation surprised many of his former admirers, as observed at the time. As his faith deepened, de Plancy, in later editions, thoroughly revised the Dictionnaire de Inferno to conform it to Catholic theological views.
In the sixth edition published in 1863, de Plancy added many illustrations and affirmed the existence of the devil. He collaborated with French priest Jacques Paul Mignet to write the Dictionary of the Occult Sciences, or Encyclopedia of Theology, which is considered an orthodox Catholic work.
De Plancy's essays in the Dictionary of Infernal Affairs reveal his vacillations between reason, faith, and the will to believe without evidence. For example, he acknowledges that palmistry may have its validity:
"Palmistry, and especially physiognomy, have at least some possibility: their predictions are derived from signs related to the characteristics of the person."
In contrast, de Plancy had a negative attitude towards divination by cards, believing that these were just man-made objects that did not have individual characteristics, down to the explanation of the thousands of faces of each person.
De Plancy's transformation was not only an evolution of his personal beliefs, but also reflected the gradual acceptance of mysticism and religious beliefs by the European intellectual circles in the 19th century. His life demonstrated the dialogue between reason and faith. His past doubts gradually disappeared and turned into passionate faith. This is also a common path experienced by many intellectuals.
After experiencing the exploration of thoughts and the torment of faith, de Plancy's story gives us a profound revelation: between faith and doubt, which path will you choose to guide your beliefs?