Moore perspective-taking: An experimental investigation of the acceptability of Moorean conjunctions

The philosopher G.E. Moore first observed that making a statement and then denying that one knows or believes that statement is unacceptable. For example, It is raining, but I don’t think that is defective. Across six experiments ( n = 600), this study investigates the nature and extent of this unacceptability as a way to adjudicate between alternative theoretical explanations of this defectiveness. Results confirm that Moorean conjunctions are judged more acceptable than semantic contradictions (e.g., It is raining, but it isn’t ) but less so than felicitous conjunctions (e.g., It is raining, but it’s okay ), and this is so regardless of whether Moorean conjunctions are produced by a person or by an artificial agent such as ChatGPT. However, if the first conjunct is anchored on a perspective other than the speaker’s, Moorean conjunctions increase in acceptability (e.g., The train arrives at noon, but I think it won’t ). Several features can drive this perspective-shift, yet the acceptability of Moorean conjunctions did not match that of felicitous sentences in our sample. Our findings support the view that the unacceptability is a byproduct of mindreading, a key part of the social cognition that is crucial to using and understanding language.