What is the role of the Brotherhood in 1984?

In
, the Brotherhood is the name of the secret organization whose role is to
bring down the Party. In Part Two, Chapter Eight, whenandare at 's
apartment, the reader gets a sense of how the Brotherhood fulfills this role. Its members
murder, cheat, forge, and betray their country. In order to keep its membership and activities
secret, the Brotherhood keeps no records or membership lists.

In Part Three
of 1984, however, it becomes clear that the Brotherhood (and its head,
Emmanuel Goldstein) do not exist. This has an important effect on the Brotherhood's role:
instead of being a protest group, the Brotherhood is used by the Party to
highlight those who secretly wish to rebel. Once the Party knows
the identities of these people, it imprisons and tortures them until they relent, as we see in
the cases of Winston and Julia.