Finagle's Law of Dynamic Negatives is also known as Finagle's corollary to Murphy's Law. The term was first used by John W. Campbell, Jr., the influential editor of Astounding Science Fiction (later Analog). He used it frequently in his editorials for many years in the 1940s to 1960s but it never came into general usage the way Murphy's Law has.
Eventually the term "Finagle's law" was popularized by science fiction author Larry Niven in several stories depicting a frontier culture of asteroid miners; this "Belter" culture professed a religion and/or running joke involving the worship of the dread god Finagle and his mad prophet Murphy.
