Examine how Orwell develops the theme of the power of words in Animal Farm.
Orwell shows the power of words in the chants the pigs teach the sheep. The pigs know the power of words and especially of simplistic slogans that can be repeated over and over.
These slogans begin with Snowball. Because some of the less intelligent animals are having trouble learning the Seven Commandments, he boils them down to one: "Four legs good, two legs bad." We learn, and the pigs no doubt notice, that the sheep love this simple slogban and can repeat it over and over for hours.
When Snowball is run off the farm and Napoleon becomes all powerful, he uses the sheep's ability to bleat "Four legs good, two legs bad" for a quarter of an hour or more to put an end to discussions he doesn't want to have. When the farm is on the brink of famine, Napoleon has the sheep repeat the rumor that rations have actually increased, knowing the power of words to influence thought. When the pigs want to walk on two legs, they teach the sheep a new slogan to repeat mindlessly over and over: "Four legs good, two legs better."
Moreover, the pigs keep changing the Seven Commandments to support their increasing oppression of the other animals, finally reducing the commandments to one nonsensical statement that all animals are equal but some are more equal than others.
In showing how slogans can drown out thought, Orwell warns humans to avoid embracing simplistic statements. In depicting how the pigs can change the entire meaning of Animal Farm by changing a few words, he points out the importance of memory.