Think about Dogen : Jacob promised he would be reunited with his son if he protected the island … And he is, as we know, in the FST. So I'm wondering : did Jacob know the ones who saved the Light would be « rewarded » with the FST ? Did he just lie to Dogen, like the MIB when he's promising to reunite Sayid and Nadia ? Did he plan to let Dogen leave the island after a while ? I think the first answer's the more likely, since Desmond's case proved that if you can see the future, like Jacob does, you can see the FST, and, if you think about it, we've never really caught Jacob lying. Concealing information, yeah, but not outright lying. And since he can see the future, the third option sounds unlikely : Jacob knew he would die at the Temple. I'd like to hear your take on that !