 Tennant (2001a) takes issue with Williamson’s claim that \(p \wedge(Kp \rightarrow En)\) is Cartesian. In the case where \(n\) is odd, \(En\) expresses a necessary falsehood (for instance, ‘13 is even’). But then, line 4 tells us that \(K(p \wedge(Kp \rightarrow En))\) implies something that is necessarily false. And if the falsity of ‘13 is even’ is a matter of logical necessity, then \(p \wedge(Kp \rightarrow En)\) cannot be consistently known and therefore is not Cartesian. Hence, when \(n\) is odd, the first part of Williamson’s proof (involving the predicate ‘is even’) does in fact violate the Cartesian restriction. By contrast, Williamson’s conjunction is Cartesian when \(En\) is true. But, analogously, if the truth of \(En\) is a matter of logical necessity, then \(p \wedge(Kp \rightarrow \neg En)\) cannot be consistently known and is therefore not Cartesian. Hence, when \(n\) is even, the second part of Williamson’s proof (involving the predicate ‘is odd’) violates the Cartesian restriction. Either way, Tennant argues, Williamson has not shown that TKP is an inadequate treatment of Fitch’s paradox.