 On this (natural) interpretation of (RFM App. III), the early reviewers’ conclusion that Wittgenstein fails to understand the mechanics of Gödel’s argument seems reasonable. First, Wittgenstein erroneously thinks that Gödel’s proof is essentially semantical and that it uses and requires a self-referential proposition. Second, Wittgenstein says (§14) that “[a] contradiction is unusable” for “a prediction” that “that such-and-such construction is impossible” (i.e., that P is unprovable in PM), which, superficially at least, seems to indicate that Wittgenstein fails to appreciate the “consistency assumption” of Gödel’s proof (Kreisel, Bernays, Anderson).