In George Orwell's 1984 and Animal Farm, reality is defined by what the leaders tell the commoners it is, and the idea of individuality and free thought are abolished in order to preserve that reality. 1984 demonstrated the concept of a perceived reality versus a true reality, and Animal Farm revealed that reality is in the beholder.
The Outer Party members in 1984 were oblivious to the true reality of their lives and blindly accepted whatever was told to them. An excellent example of the Outer Party's ignorance to truth is when they are told that their chocolate rations have been increased, when actually the rations were just reduced a week earlier. Because of the Party's successful assault on the individuality of its members, people became cheerful when they heard of the news. This perceived reality is the truth to the Party members.
The true reality in 1984 is shown only to the reader and some Inner Party members.
O'Brien knows the real truth of things as shown by his torturing of Winston. He tells Winston that if the Party tells the people that 2+2=5, then it does. He also instructs Winston that if the Party informs its members that 2+2=3 or 4 or all at the same time, then it is so. Although this true reality is available to Inner Party members, they too do not have the freedom of thought or individuality... they are only just aware of its existence. Only the outside reader is able to think and understand the true nature of the reality established by the Party.
In Animal Farm, Orwell unveiled that reality is a simple mental state that can be easily manipulated. Napoleon and the pigs proved this theory by repeatedly changing the Seven Commandments and reporting to the other...