The relationship between language and thought

Question: Why is the ruthless totalitarian regime, described in Orwell’s novel purging Oldspeak and imposing Newspeak? What assumptions are being made about the relationship between language and thought?

Answer: In Orwell’s novel, the people whom are supportive towards the idea of the imposition of Newspeak clearly state that the thought and language walk together 'hand in hand', and believe that destroying the oldspeak, would be more of an efficient way of communication. They serve the idea that in order to be able to understand a certain concept of a word the need of knowing its defintion/explanation is the only way in which we will be able to understand it or even bring it in our daily life or in other words, how can use something that does not exist?
For instance, in our minds we think in typical a language, we use different adjectives to describe our feelings, meaning that if these specific words to how we feel did not exist we would feel this way or basically be limited in our thoughts or even expressing our emotions. A great example is when the Spanish colony had took over South America in the 15th century. They claim that, when the people who have seen the Spanish ships heading towards their coast could not protect themselves since they did not know what they were standing against, they did not know all the concept of 'sailing' or what were 'Ships' therefore they could not THINK of it as danger, or in other words they were just staring at an unknown object coming towards them. This just shows that in order to think of something and have an opinion about it, knowing its concept is a must to really and fully understand it.