because in order to complete the circle of life, the new protector will have to actually destroy the MIB. Essentially, Jacob knows that the MIB will eventually ﬁnd a way to kill him, but that whoever replaces him will also have to kill the MIB. This is no easy feet due to him no longer have a corporeal form. Thus, the need for so many candidates to begin with. With this cycle, it's not just as simple as guarding the source. Since both Jacob and MIB are bound to the source, they both need someone to unplug it, as they cannot. However, the MIB needs someone to do it so he can leave, whereas Jacob needs someone to do it so that they can kill the MIB and complete the cycle. The reason Jacob puts so many of the candidates through hell, is to prepare them for what they have to do. Meanwhile, MIB is manipulating them to destroy one another and the island. The dharma initiat ive nicknames the smoke m onster cerberus. Cerberus was the guard of Hades. Usually, the protector is both the sides of the equation, but due to the dichotomy between the two, the MIB becomes the incarnation of only one part.

No one has all the answers

One of the running themes of the show is faith versus science. I believe that no one really has the answe rs. Jacob doesn't reall y know what the source i s anymore than he explained. The MIB doesn't exactly know how to get off the island or what will happen when you pull out the cork. Both characters know m ore than the Oceani c 815 survivors, but are also in the dark about many things. They are acting on faith and basically guessing . They just understand that l ight is the source of the struggle.

Time Travel, Moving the Island, and why people can't have babies.