I just got this wierd feeling reading another post...what if at one point MIB and Jacob were the same personand this is just a case of split personalities? showing that all have some good and bad in them. I know we have seen them together at points in the show and the sriters have said we have not seen Jacob in any other form than what he was on the beach, but i could see this being something like that. It doens't make sense that Jacob just let Ben kill him without a fight, Ben saying that everything needs to be as much like the first flight as possible, so Lockses body would be on the flight. the canidates on both the lighthouse and cave? Ben taking orders from Jacob but seems like they have been from MIB?