In 1984, George Orwell has embodied all his fears about the destructive effects of a totalitarian regime. In this novel, the Party writes and rewrites history (including the very existence of its friends and enemies), and the face of the Party is Big Brother. In this world Orwell has created, truth is relative, and Big Brother maintains power by controlling the minds of the people (a term I use loosely here).
The national slogan of Oceana sets the tone for the kind of deception and double-dealing (known as "double-speak) Big Brother does with language:
War is Peace
Freedom is Slavery
Ignorance is Strength
Obviously, in the world of Big Brother, truth is relative; more importantly, the ability to make people accept a lie as truth is the mark of true control. Early in the novel, Winston asserts this truth: “Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.”
Winston already knows that Big Brother is powerful enough to control the past and the future (physical realities), but he had hoped that it would not be able to exert the same kind of control over the mind--until he reads this:
In the end the Party would announce that two and two made five, and you would have to believe it. It was inevitable that they should make that claim sooner or later: the logic of their position demanded it. Not merely the validity of experience, but the very existence of external reality was tacitly denied by their philosophy.
Winston does not conform like the others, and he is constantly exploring the relationship between the mind and reality. If reality exists only in the mind and the Party controls the mind, there is no hope at all, for then the Party controls everything.
Winston thinks, “For, after all, how do we know that two and two make four? Or that the force of gravity works? Or that the past is unchangeable? If both the past and the external world exist only in the mind, and if the mind itself is controllable—what then?”
When Winston is finally caught and taken to the Ministry of Love, he is tortured until he finally screams that 2 + 2 = 5 and the Party deems him fit to be released back into society. In the last chapter of the novel, Winston is sitting at a table in the bar where he used to play chess. He writes the faulty equation in the dust on the table and drops the white knight onto the board in a kind of defeat.
If the Party can control the mind, it can control reality. This slogan (and the true equation, 2 + 2 = 4) is representative of the Party's ability to control the mind. it is a motif that begins early in the novel and is seen consistently until the end.