6.1263 It would indeed be all too remarkable if one could prove a meaningful [sinnvollen] proposition logically from another, and a logical proposition too. It is clear in advance that the logical proof of a meaningful proposition and proof in logic must be two completely different things.

Logical propositions are not sinnvollen, of course. Proof in logic must not be proof of sinnvollen propositions. But can there be logical proof of such propositions? He doesn’t say. If there is, though, it must something other than “proof” in logic.