 One cause of the muddle is Wittgenstein’s insistence that there must be a distinction between obeying a rule and merely thinking that one has. This does not result, as the Orthodox have supposed, in a demand for, and eventual rejection of, ‘memory-infallibility in a private language’: demand and rejection being based respectively on the grounds that without infallibility one could always be going wrong and would never know if one were, and with infallibility one would collapse the distinction between obeying a rule and merely thinking one was obeying it. Rather, the argument is this. The private linguist cannot legislate a meaning for a sign by “private ostensive definition” merely—for this has to establish a technique of using the sign (§260). The technique cannot function by means of repeated “ostensive definitions”, as we saw in examining the first answer, since this collapses the distinction between meaning and truth and thus destroys the possibility of making factual judgments. So the so-called “definition” has on some other basis to establish a constancy in use of the sign.