K. argues that the notions of 'purported belief' and 'purported knowledge' can be reduced to Hintikka's notions of 'doxastic implication' and 'epistemic implication', from which he develops the concept 'pragmatic implication'. K. suggests that the concept of pragmatic implication can serve as an explication of the notion 'pragmatic presupposition' and that it should be one of the basic terms in a pragmatic language.