Conceptions of Protocol Sentences in Carnap and Neurath

Discussions of protocol sentences, for obvious reasons, tend to focus on the period of the protocol sentence debates, whilst discussions of Neurath and Carnap’s later work tend not to concern protocol statements, instead typically focusing on semantics, explication and the unity of science. But important elements of the compatibility of Carnap and Neurath’s respective projects can be gleamed from an examination of their respective notions of protocol statements, as presented in their later works. With this in mind, the purposes of this article are threefold. First, to elaborate the mature conceptions of protocol statements held by Carnap and Neurath. Second, to explicate and defend Neurath’s conceptions of protocol statements in the face of potential disagreements and misunderstandings. Third, through the introduction of a terminological distinction, to demonstrate the compatibility and complementarity of Carnap and Neurath’s conceptions of protocol statements, and how this further demonstrates the complementarity of their respective meta-scientific projects. In so doing, this article provides further support for Uebel’s bipartite metatheory thesis.