How does Orwell use the symbol of the memory holes to deepen the aesthetic impact of the novel and develop the theme?

In Part One, Chapter Four, of 1984, the reader is first introduced to the memory hole. These holes are prevalent in the Ministry of Truth, where Winston works, and are used for destroying scraps of paper. These scraps, however, contain documents from the past and are transported via the memory hole to the "enormous furnaces which were hidden somewhere in the recesses of the building."

The memory hole, then, is a symbol of the...

In Part One, Chapter Four, of 1984, the reader is first introduced to the memory hole. These holes are prevalent in the Ministry of Truth, where Winston works, and are used for destroying scraps of paper. These scraps, however, contain documents from the past and are transported via the memory hole to the "enormous furnaces which were hidden somewhere in the recesses of the building."

The memory hole, then, is a symbol of the party's control over information. As we see in Chapter Four, Winston destroys documents from the past, like the claim that the party would not reduce the chocolate ration, and replaces them with party-approved information. In the case of the chocolate ration, for instance, Winston creates a new document which states that a ration would "probably be necessary in April." This not only boosts the prestige of the party but also makes it appear as though Big Brother has the interests of the people at heart. 

In the wider context of the novel, the memory hole also represents the party's ability to control the past. By destroying memories and installing new ones, the party moulds and shapes popular understanding of Oceania's history. The problem with accepting the party's version of history, however, is that people will come to accept anything that the party tells them.

Like Winston says, in Part One, Chapter Seven, if the party declares that "two plus two equal five," then, sooner or later, one has no choice but to believe it.