People are doing things they personally do not understand, just by following the rules, all the time. One does not need to understand why celestial navigation works in order to do it, for example. Heck, most kids can learn arithmetic (and perform it in their heads) without being able to explain why it works, and many (including their teachers, sometimes) never achieve that understanding. Searle’s failure to recognize this very real possibility amounts to tacit question-begging.