Scientologie, Wissenschaft von der Beschaffenheit und der Tauglichkeit des Wissens (Scientology: Science of the Constitution and Usefulness of Knowledge) is a 1934 book published by Anastasius Nordenholz, in which he defines the term "Scientologie" or "Eidologie" as a science of knowing or knowledge and discusses the philosophical implications of the concept. The book has been cited by some as a possible source of inspiration for L. Ron Hubbard and his better-known conception of Scientology, though this interpretation is disputed.