Johann Konrad Dippel, a German mystic and rationalist, born at the castle of Frankenstein, Hesse, Aug. 10, 1073, died at Berleburg, April 25, 1734. He was the son of a elergyman, and at an early age showed a strong interest in religious matters. He studied theology at Giessen and philosophy at Wittenberg, and went subsequently to Strasburg, where he led a disorderly life, and had to leave the city, it is said, on account of being implicated in a bloody affray. He frequently appeared as a preacher, and also as a lecturer on astrology and chiromancy, and published in 1697 a pamphlet entitled Orthodoxia Orthodoxorum, and in 1098 another, called Papismus Protestantium capu-lans, in which he attacked the orthodox party, rejecting the doctrines of the atonement and of the efficacy of the sacraments. He was consequently obliged to lead a wandering life to avoid prosecution. Having squandered his property in experiments in alchemy, he went to Leyden, obtained the degree of doctor of medicine, and began to practise as a physician. He published subsequently some other pamphlets, one of which, entitled Alea Belli Muselman-nici (Amsterdam, 1711), caused his exile from Holland. He went to Denmark, where he continued to declaim against the clergy and the churches, for which he was arrested and imprisoned.

After his release he went to Sweden, where he practised as a physician with considerable success; but having published a pamphlet regarded as heretical, he was expelled from the country and soon afterward died. He acquired much scientific knowledge and made some valuable discoveries. The main point of his doctrine was that Christianity consists solely in the practice of virtue, of self-denial, and love for mankind. He published his writings under the name of Christianus Democritus (collected under the title of Eroffneter Weg zum Frieden mit Gott und alien Creaturen, Amsterdam, 1709; enlarged ed., Berleburg, 1743). He attracted much notice in his day in Sweden and Germany, and is frequently mentioned by Sweden-borg in his "Spiritual Diary." His biography was written by Ackermann (Leipsic, 1781), and Buchner has given a memoir of him in the Historisches Taschenbuch for 1858.