The illocutionary structure of definitions in Frege’s early logic

My aim in this paper is to discuss Frege’s perspective on definitions especially considered from the point of view of their illocutionary structure. In particular, I shall examine Frege’s view on: (i) the differences between defining and accepting axioms (or asserting true propositions in general); (ii) the propositional content of definitions; (iii) the question whether definitions (that are not just abbreviations) have any impact on the ontology of mathematics. As I shall try to show, Frege has a quite original view in all of these topics, a view that has largely been ignored in the logic tradition after him.