Some of the allusions that Orwell employs in 1984 are meant to deliberately contrast the world of Oceania with the reader's reality. In employing these allusions, Orwell is able to make vital statements about Oceania and the condition of what is and what should never be.
One set of allusions early in the text can be found in Part I, Chapter 3. The first one is an allusion to Shakespeare. Winston wakes up from a dream in which various images of his mother and a naked woman, and utters "Shakespeare:"
With its grace and carelessness it seemed to annihilate a whole culture, a whole system of thought, as though Big Brother and the Party and the Thought Police could all be swept into nothingness by a single splendid movement of the arm. That too was a gesture belonging to the ancient time. Winston woke up with the word 'Shakespeare' on his lips.
The allusion to Shakespeare is deliberate. Shakespeare wrote about the complexities of emotion and the ambiguities that exist within the human predicament. Shakespeare writes of a world where there is complete disunity and a sense of complication in everything human. This is not the world of Big Brother, where human freedom and endeavor have been reduced to the smallest of quotients. Shakespeare depicts a world in which tragic collisions construct what it means to be human. The allusion is deliberate because the world of Big Brother has removed all such human expressions and replaced them with consolidation of centralized power.
A socio- historical allusion can be seen in the same chapter when Orwell is describing the perpetual state of war. Oceania is described as a setting where one cannot recall a time of peace: "Since about that time, war had been literally continuous, though strictly speaking it had not always been the same war." The fact that wars are "invented' in other settings and are continuous is an allusion to the Cold War that emerged at the time of Orwell's writing. The Cold War allusion helps to illuminate the centralized tendency of Oceanic government. In being able to continually declare wars, dissent and personal expression are negated in the name of perpetual conflict. War represents the strength of the state. Orwell's allusion to Cold War politics helps to underscore how the novel speaks to a modern condition where nations declare war as exercises of power for control over their populace, as opposed to endeavors of peace.
In Part III, Chapter 2, Winston experiences the full power of centralized control. When he is tortured in Room 101 at O'Brien's hands in order to reeducate him, Winston makes an allusion to Descartes:
'I think I exist,' he said wearily. 'I am conscious of my own identity. I was born and I shall die. I have arms and legs. I occupy a particular point in space. No other solid object can occupy the same point simultaneously. In that sense, does Big Brother exist?'
Prior to this, O'Brien had referenced that Winston is not a "metaphysician." The allusion to philosophy in this section is deliberate. Cartesian notions of philosophy have served as the basis for Western liberal thought. They helped to establish personal freedom and space free from external encroachment. In Room 101, there is no personal freedom and nothing but encroachment. O'Brien emphasizes to Winston that there is no freedom and only what Big Brother demands. As with the allusion to Shakespeare, it is effective in displaying the world of Oceania and illuminating a world that terrifies the reader's sensibilities.