There are a number of themes that you can identify in this book. You should follow the link to read what eNotes has to say about the themes.
To me, the major theme is that power corrupts people. I think that Orwell is trying to tell us that even people who start out very idealistic can become corrupted. You can see this in how the pigs start out with Old Major's vision but are exactly like the people (oppressive) by the end of the book.
I would say that another theme is that people who are idealistic end up getting exploited and then oppressed by those who are power-hungry. I think you can see this especially in the character of Boxer. He is very idealistic but ends up getting worked to death by the new regime (which then essentially sells his body).
I would go along with others to suggest that one of the main themes is that absolute power corrupts absolutely, which we see once the pigs become identical to the humans at the end of the book.
But an important thing to remember is that Orwell was very purposely focusing on the individuals involved in the rise to power of the communist government in the USSR and the various contentions and problems within that government. The book is not just about power but about how the various people interacted and his view of, for example, Trotsky being driven out because he was in fact too concerned with helping the average person.
I like the idea of "meet the new boss, same as the old boss." Orwell was really ahead of his time in understanding how the government of nations such as the Soviet Union were not really transformative in how their government functioned. They were just better at packaging it and selling it as something distinctively different. Orwell's depiction of Napoleon and his drive for power, the practices of consolidating it in order to ensure that there is no threat, and the reduction of individuals to atomized part whose submission will either be received or simply be discarded is reflective of the theme of power corruption, as suggested in the previous post. At the same time, I think that another theme here is that in order to avoid this, there has to be courageous individuals, and quite a few of them, to make sure that government is responsive to the needs of its people. The lack of a courageous figure and quite a few of them is something that allows Napoleon to get away with what he does. The enotes analysis of the themes in the book would also be helpful to you.
The weakness of all Utopias is this, that they take the greatest difficulty of man and assume it to be overcome, and then give an elaborate account of the overcoming of the smaller ones. C. K. Chesterton, Heretics
I think the above quote states pretty accurately what Orwell had in mind. Changing institutions does not change human nature, which is "the greatest difficulty of man." Some people will work hard, cooperate, and share with others, but there will always be those who don't want to work, don't want to share, and don't want to cooperate. And there will always be the ones who want to tell the others what to do.
B. F. Skinner's novel Walden Two is a good example of a utopian experiment in which a large commune functions perfectly because the author, a famous psychologist, ignores the differences in human character and simply assumes that everyone will live in harmony and common purpose. A different picture of a utopian commune is to be found in the infamous Jonestown Massacre, where over nine hundred people were persuaded by the monomaniacal leader to commit suicide.
Please refer to the links below.
One main theme that I always keep in mind is one where history is bound to repeat itself if one is ignorant to the past. The animals had disregarded their prior knowledge of the events that had occurred and the emotions that conveyed those events, so history was set into the same cycle once again. Never be ignorant to he past, or you can't help yourself in the future.
Hope this helped! I just did a few reports on this paper myself.
The them thi animal farm is power corrupting us.Napoleon an the piArden up beig just as controlling and manipulation as humans. Taking advantage of the not so smart animalwand making their lives easier. They judged the humans so badly for it an ended up being maybe even worse . At the end of the novel that's why you can't tell the difference between the pigs and the humans.