A person x and a person y can t have the same 1 sensations. A person x and a person y can t have the same 2 sensations. In my opinion Wittgenstein gives in his works two different arguments to justify this claim. And it is my aim to show that this argument is confronted with struggling problems. We have to revise our assumptions to understand Wittgenstein claim.
Sensations are private.
And this fact can be justified. Rules of grammar are neither true nor false. If someone asserts a proposition that is a rule of grammar then he asserts the truth of this proposition. The problem of this definition is that it is too narrow, because we also call assertions of propositions, which aren t rules of grammar, nonsensical. Wittgenstein calls such propositions grammatical propositions .