“What is abduction?” asks Jaakko Hintikka in the title to his 1998 article on C. S. Peirce’s concept. The answer to Hintikka’s question is problematic on several counts. There is, to begin with, a difference between Peirce’s own views on abduction and later interpretations of abduction as “inference to the best explanation” (Minnameier 2004; Paavola 2006). There are, furthermore, tensions within Peirce’s own account of abduction, for instance, a tension between “inferential” and “instinctual” aspects of abduction (Fann 1970; Anderson 1986; (...) Kapitan 1990; Paavola 2005; Paavola and Hakkarainen 2005). These tensions are exacerbated by two factors. First, there are several terminological variants of the word.. (shrink)