 Finally, critics argue that the problem with #4 is that there is no evidence for the claim that the relevant operation is logical in Wittgenstein’s or Russell’s or Frege’s sense of the term—it seems a purely formal, syntactical operation. “Logical operations are performed with propositions, arithmetical ones with numbers”, says Wittgenstein (WVC 218); “[t]he result of a logical operation is a proposition, the result of an arithmetical one is a number”. In sum, critics of the Logicist interpretation of the Tractatus argue that ##1–4 do not individually or collectively constitute cogent grounds for a Logicist interpretation of the Tractatus.