Ben Linus's secret / What is Dead? / What are the Whispers? by Charles Mark Carroll

"I know what you are boy" - Widmore to Ben

Widmore did NOT say "I know WHO you are". This always intrigued me.

Lets operate on the assumption that death is accompanied by the soul separating from the physical body. In some cases the souls become ghosts (the kind Miles talks to) and in other cases they vanish to another plane and in some cases they fill a baby (reincarnation). That happens normally everywhere in the world except on the Island where the soul becomes separate from bodies and get trapped inside the Island "snowglobe" i.e. the energy field that surrounds the Island and the surrounding ocean. Basically the energy field that encloses what moves when the donkey wheel "jiggles" the exotic matter. This is the field Faraday remarked "The Zodiac must have been inside the field" and the field that ensured the Island and small surrounding Islands move as a group together in time/space...

I believe the indigenous population of the Island are disembodied spirits - people who died on the Island but their souls are unable to ascend. The Island's various energies block the souls from leaving the Island. These souls are the Whispers.

The Temple Elders can help "pour" souls into corpses. It is a form of forced reincarnation. However the vessel is unaware of the soul within, the switches from one brain/controller to another are instant and unknowable by the vessel.

The Smoke Monster can "judge" a body as a candidate to know what it was pouring a soul into, thus it "flashes" them to learn about people.

Ben was born on the Island as he said. The Ben Sayed killed became a corpse -- a vessel for Temple Elders / Smokey / Indigenous spirits to fill with another soul probably the soul of someone that was an Island native from long ago. The Ben we know is someone else's soul poured into Ben's body sharing it with him.