  While this is only to be expected on views which maintain that ‘the number two is green’ is meaningless or at least contentless, it is arguably a less palatable consequence for the truthvaluelessness view. An alternative view which avoids this consequence is an account of category mistakes using supervaluationist logic. The view is developed in detail in Thomason (1972), but in broad terms it proceeds as follows: a valuation is an assignment of the values true/false to each atomic sentence, where unproblematic instances receive truth values as usual and category mistakes are assigned an arbitrary truth value. Complex sentences receive a truth value relative to each valuation in the standard recursive manner, and finally a sentence is considered true if it is true relative to every valuation; false if it is false relative to every valuation; and truth-valueless if it is true relative to some valuations and false relative to others. This ensures that (23) is deemed true because it is true relative to every valuation (one can prove that the same holds for all other classical tautologies). Moreover, it also deems existential quantifications such as (20) true and hence correctly predicts that they are felicitous. However, as with the SK approach, the supervaluationist treatment of category mistakes renders both (21) and (22) to be truth-valued, and hence (incorrectly?) predicts that they are felicitous.