One of the more troubling aspects of Animal Farm is the realization that unchecked power has the potential to corrupt individuals. If understood in its intent, this is a very frightening story. It illustrates the immense responsibility that individuals have in order to live in a "free" society. It is the responsibilty of those living in a free society to educate themselves. Without doing so, individuals are at the whim of those who possess the education. It's clear in the story, that Napoleon (and the other pigs) wanted to keep the other animals "in the dark." It was in their best (perverted) interest to have the animals beholden to them. Orwell clearly was attacking the idea of an unsuspecting populace. The other animals on the farm, not knowing any better for lack of understanding, followed the dictates of those "in the know."
Lastly, the reader gets a good "education" themselves on the power of language as well. The pigs use language (and their mastery of it) to manipulate the other animals so that their wishes (the pigs) are met. And why not? "It's good to be the king," right? You get to do as you wish with no consequence. Eat what you want, live as you wish, have others do work for you, etc. Who needs this "responsible citizen" nonsense? Orwell's story poses some very important points about what it means to be a human being. How does one overcome these desires to live without regard for others? What would possess one to live with the greater good in mind? Why bother? This is the same sort of argument that Plato deals with in The Republic, i.e., that inside of each of us is this idea of The Good. And it is this Good that humanity needs to pay heed to over the darker side of human nature. As Lincoln said, (I'm paraphrasing) "we need to pay attention to the angels of our better nature."