There are many lessons that we can learn from the book, Animal Farm. In light of this, let me name three points.
First, we can learn that things might start off with noble reasons, but when it comes to execution things might fall apart and turn ignoble. The perfect example of this is the desire for a revolution. At first, the desire for a revolution was rooted in the unjust treatment of the animals, but when the revolution came about, the animals were actually worse off under the bloody tyranny of Napoleon.
Second, absolute power corrupts absolutely. It is a cliche to say this, but as we read the story we see that this point is true. In fact, by the end of the story the pigs turn into humans. This transformation shows that the pigs are now taking the place of humans. Power has corrupted them, and life is worse under the pigs.
Third, the use of rhetoric is powerful. Throughout the novel, we see the silver-tongued Squealer spewing his propaganda and rhetoric. He is surprisingly successful. The animals believe in his every word; they even doubt their own memories and intelligence. This shows the power of rhetoric.