  Some critics have doubted that the introduction and elimination rules for the logical constants exhaust the aspects of the use of these constants that must be mastered if one is to understand them. For example, it has been suggested that in order to grasp the conditional and the universal quantifier, one must be disposed to treat certain kinds of inductive evidence as grounds for the assertion of conditionals and universally quantified claims (Dummett 1991, 275–8; Gómez-Torrente 2002, 26–7; Sainsbury 2001, 370–1). It is not clear that these additional aspects of use can be captured in “purely inferential” rules, or that they can be derived from aspects of use that can be so captured.