Carnap Ponders Canberra: Creating a Theory of Meaning Based on Carnap’s Criteria of Cognitive Significance and the Canberra Plan

Although logical positivism has fallen out of favor within many philosophical circles, one might remain sympathetic to the logical positivists’ critique of the meaningfulness of philosophical terms. In an attempt to address this open problem, I will propose an updated theory of meaning by combining the Canberra Plan methodology and Carnap’s four criteria of cognitive significance as explicated in “The Elimination of Metaphysics Through Logical Analysis of Language”. I will argue that of Carnap’s original criteria, the notion of protocol sentences (C2) and verification (C4) remain problematic. I will further argue that protocol sentences can be replaced by step-one of the Canberra Plan. This shift towards Lewis’ more robust conception of O-terms as any known/old terms will still limit the types of terms that are meaningful yet proven to be less problematic than Carnap’s notion of observation terms. Additionally, I will argue for the replacement of verification with a modified version of step-two of the Plan. Due to the emphasis of locating a unique realizer within the Canberra Plan, I will propose two types of meaningful terms: meaningful with a located unique realizer (MLR), and meaningful but an absent unique realizer (MAR).