  It is certainly true that the conclusion reiterates part of what was prescribed in the premise. And yet I may hesitate to tell someone to light the fuse, even when I am happy to tell him to light the fuse and step back, if I know that, given his tendency to be carried away, he is most likely, if he lights the fuse, not to remember to step back. (As we might put the point in terms of possible worlds, I won’t tell him to light the fuse if the closest world to this one in which he lights the fuse is one where he forgets to step back; indeed, one solution is to require, for the inference to go through, the addition of a factual premise to the effect that if he lights the fuse, he will remember to step back.) And how can I be telling someone implicitly to do a thing that I would be unwilling to tell him to do explicitly?