 By 1880, C S Peirce, in America, had clarified the basis of deductive inference and, although acknowledging induction, also proposed a third type of inference.Peirce called it "abduction", now otherwise termed IBE, "inference to the best explanation".Since the 1920s, rebuking metaphysical philosophies, the logical positivists, accepting hypotheticodeductivism on the origination of theories, sought to understand scientific theories as provably false or true as to merely empirical facts and logical relations.