Sort of like the set of stupid questions asked by lawyers that was published a while ago. As I recall, one went about like this:
Lawyer: Can you be sure the man you examined was dead?
Coroner: Yes, I can.
Lawyer: But how can you be absolutely certain the man you examined was dead?
Coroner: Because his brain is sitting in a jar on my desk.
Lawyer: But aren’t there some circumstances in that case where the man wouldn’t be dead?
Coroner: Yes, I suppose he could be alive and practicing law somewhere.
Occam