Quine on the Intersubjectivity of Observation Sentences

W. V. Quine developed two naturalistic clarifications of the idea that observation sentences are intersubjective—the clarification he first proposed in Word and Object (1960) and the one he first proposed in “Three Indeterminacies” (1990b) and Pursuit of Truth (1990a). My goals in this paper are to examine both clarifications and to develop a consistent and defensible version of the second one. To shed light on these issues I examine Quine’s and Davidson’s extended discussion of the intersubjectivity of observation sentences at the 1986 Stanford Quine Conference. During this discussion Davidson argues at length that we have no idea how to specify, in physiological or physical terms, resemblances between events of neural stimulation, or facts about physical forces at or close to a person’s body, that are present when and only when we judge, by our ordinary criteria, that two speakers jointly witness the same event. Davidson’s arguments convinced Quine to abandon his first main account of observation sentences and seek to develop a new one. Combining Davidson’s arguments with others that Quine had voiced himself as early as 1965, I reconstruct and defend of the account of observation sentences that Quine develops in “Three Indeterminacies,” Pursuit of Truth, and later works.