Conscientiarii (conscience people), the name of a sect of atheistic freethinkers in the 17th century. The founder of the sect was a student of theology at the University of Jena, Matthias von Knutsen (also called Knuzan or Kuntzen), born at Oldensworth, in Schleswig, who, while studying at Jena (in 1674), circulated among the students two writings, in which he denied the existence of God, the authority of the Bible, and the difference between marriage and fornication, recognizing only the individual reason and conscience (hence the name) as rules of religious belief. Knutsen claimed to have numerous adherents at all the universities and capitals of Europe, at Jena no less than 700, and thus brought the university into bad repute. The professors of Jena indignantly denied his assertion. The excitement produced by the discovery of the agitation of Knutsen soon died out, and the Conscientiarii were no longer heard of. See Wetzer u. Welte, Kirch.- Lex. 2:815; Arnold, Kirch. u. Ketzerhist. vol. 2.