1: WAR IS PEACE, FREEDOM IS SLAVERY, IGNORANCE IS STRENGTH
These words are the slogan for the Ministry of Truth. According to the Party, War is Peace because a common enemy keeps the citizens of Oceania united as one. Freedom is Slavery because apparently, the independent man is destined to fail. Also, Slavery is Freedom, because a man that is controlled by another's will is free from danger and desires. Lastly, Ignorance is Strength because the incapability of the Proles to recognize the contradictory messages results in a powerful, stronger Party. However, this slogan is obviously an example of doublethink, where people hold these extremely contradictory ideas in their minds to accept anything the Party decrees. For example, not only these words, but the names of the ministries themselves- Minitrue (Lies and Propaganda), Minipax (War), Miniluv (Torture and brainwashing), and Miniplenty (Rationing and shortages) are everyday examples of the amounts of doublethink the population is exposed.
Although not as severe and authoritarian as the Party of Oceania, there are many countries in the world that used these methods to control and manipulate their people. For example, among the many communist nations in the 20th century, the Soviet Union used disinformation and used language to manipulate their population. I believe that this slogan describes the first section because as the first section introduces and describes the ultimate power of the Party, the slogan describes how the Party uses doublethink to manipulate and control the population.
2: Who controls the Past controls the Future.
Who controls the Present controls the Past.
The Party has complete dominance and power in the present. With that power, the Party assigned the Ministry of Truth to rewrite the past- every single history book has Party ideology written all over, and because citizens are not allowed to keep journals or photographs of their own pasts, the people of Oceania have a very unreliable, fuzzy memory before the Party took control, and instead believe whatever the Party tells them. Also, in the end, O'Brien reveals to Winston that the past is not real; it is only imagined in the minds of humans. Therefore, according to O'Brien, because the people believe the Party's version of history, although it was not actually real, the Party's version of the past is the truth.
This is an interesting slogan. In the many dictatorships and authoritarian regimes that occurred in human history, the dictators or the ruling minority almost always destroyed the books or documents that disagreed with their ideology or their explanation of events; for example, in Hitler's Nazi Germany, thousands of Jewish books as well as books about different ideologies were burnt in huge bonfires. In many cases, some totalitarian kings that usurped the throne either burnt the existing history books or rewrote new history to make themselves seem "right" in the eyes of their subjects. This, along with the first quotation, clearly defines the first and second portion of the novel because it defines the absolute power of the Party. The Party is powerful enough to rewrite history and to have its subjects to accept the constant changing of facts.
3: "They can't make me stop loving you- that would be the real betrayal."
In the middle portion of the book, Winston and Julia begin a passionate, illegal relationship carefully hidden from the Thought Police and the Party. However, especially Winston, both of them realize that sooner or later, they will get caught by the Police and tortured until each admits to betraying one another. To comfort the depressing, horrifying thought, Julia says, "They can torture me and make me say 'I hate you', but they can't make me stop loving you- that would be the real betrayal." They believe that the Thought Police will no doubt torture them and force them to admit their treason and love the Party once again, as well as force them to renounce their love for one another, but deep down inside, they would not be able to psychologically, mentally force each to stop loving each other. It is sad how completely easily that statement was broken, when Winston (After months of torture) and Julia both honestly betrayed each other. However, it can be seen that the quote was a comfort for the fear of the upcoming nightmare.
This quote signifies human hope. Sure, in the battle of Thermopylae, 300 Spartans faced against hundreds of thousands of Persians, the battle was quite hopeless for the Spartans. However, knowing that their end was coming, they still didn't back up and flee in fear. Just as Julia and Winston stayed their ground and refused to worry, the Spartans stayed their ground until the very end. No matter what the massive odds are, hope will still remain.
4: 2+2=5
2+2=5 is a slogan created by the Party. During Winston's stay in Miniluv, O'Brien tells him, "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?" 2+2=5 is a form of psychological manipulation and control that the Party used to ensure acceptance of the Party's decrees, as well as being used by O'Brien to check Winston if he had finally accepted the Party's teachings during the torture. When Winston finally gave up and said 2+2=5, it signified that Winston had given up on his ideas and opinions and finally accepted the Party's ideas and teachings. 2+2=5 symbolizes the complete mind control the Party has on its subjects: how badly are you manipulated and controlled if you truly believe someone saying a fact that completely contradicts everything you've learned in your life?
This form (Although minor) of manipulation has occurred before, when ancient people worshiped kings and pharaohs as god-kings. After all, a king's word is law, and the king is always right, unless you want your head served on a pike. Because people allowed themselves to believe whatever their king told them, it resulted in a oligarchy where the ruling elite completely dominated power over the peasant majority.
These quotes/slogans are the messages that Orwell was sending us; the dangers of totalitarianism and authoritarian regimes.