In 1984, why does O'Brien say prisoners are brought to the Ministry of Love?

In Book 3,
Chapter 2 of s ,is being tortured and interrogated by OBrien. This is a
crucial section of the story because it reveals the true intentions of Big Brother (aka the
state). Ironically, the location for this section is referred to as the Ministry of Love. What
Winston and the other prisoners endure here is, to our way of thinking, anything but love. We
would probably call it something more like the Ministry of Brainwashing or the Ministry of
Torture.

The readers, like Winston, assume that the states goal is to punish
wayward citizens and to frighten them into behaving appropriately. However, as Winstons
interrogation proceeds, the reader sees that OBrien is not simply torturing him for information
or to change his behavior, but is actually trying to change his thought process. This idea is
demonstrated as OBrien holds up four fingers and asks Winston to tell him how many fingers he
sees. Winston insists that he sees four until the pain of the torture becomes too great, and he
seems to begin to doubt that he really sees four. OBrien is making him compliant, able to
believe what he is told even if it flies in the face of reason and common sense.

Finally, near the end of this sequence, OBrien tells Winston what the ultimate goal of
the torture process is:

We shall squeeze you empty, and
then we shall fill you with ourselves.

So, the Ministry
of Love functions to create citizens that will obey the state not only out of fear, but also
because they have been brainwashed to believe that the state is actually right about
everything.