Practical Moore Sentences

I discuss what I call practical Moore sentences: sentences like ‘You must close your door, but I don’t know whether you will’, which combine an order together with an avowal of agnosticism about whether the order will be obeyed. I show that practical Moore sentences are generally infelicitous. But this infelicity is surprising: it seems like there should be nothing wrong with giving someone an order while acknowledging that you do not know whether it will obeyed. I suggest that this infelicity points to a striking psychological fact, with potentially broad ramifications concerning the structure of norms of speech acts: namely, when giving an order, we must act as if we believe we will be obeyed.