 Since linguistic intension is implicitly holistic and verbal definition eventually circular, Lewis (1929, 107) said in MWO that logical analysis isn’t reduction to primitive terms, but is a matter of relating terms to each other. Concepts consist in relational structures of meaning. They require criteria of application in experience and the total meaning of a term for an individual consists of the concept it expresses and the sensory criteria for its application. Yet, the latter needn’t be identical across individuals for there to be common concepts, Lewis argued (1929, 115). Instead, common concepts just require shared structures of linguistic definition and common or congruent modes of behaviour, in particular co-operative behaviour that is guided by these concepts, a social achievement of a common world that Lewis thought our community of needs and interests produces. One problem with this suggestion was pointed out by Quine (1960) in Word and Object with his indeterminacy of translation argument. From the standpoint of an interpreter, there can be alternative translation manuals or schemes that are consistent with the total set of a speaker’s verbal and other behavioural dispositions. This is a problem that Lewis (1946, 144–5, 164) may have been aware of in AKV. In any case, in AKV he seems to draw back from the discussion of common concepts in MWO and to rest content with pointing out that any attribution of linguistic meaning or sense meaning to another is inductive and thus only probable, and any attribution of linguistic or sense meaning similar to ours is likewise inductive, fallible, and problematic.