The original laws of Animalism are created from the utopian ideals of Old Major's philosophy, and place great importance on equality and fairness. Because he is subverting the philosophy, Napoleon cannot have laws that overrule his ultimate power as dictator, and so he slowly changes and erodes the ideals until they fit his needs. The first change is so subtle that it goes almost unnoticed, as the pigs move into the farmhouse to sleep in the beds, which was forbidden in the commandments:
"...very comfortable beds they are too! But not more comfortable than we need, I can tell you, comrades, with all the brainwork we have to do nowadays. You would not rob us of our repose, would you, comrades? You would not have us too tired to carry out our duties? Surely none of you wishes to see Jones back?"
(Orwell, Animal Farm, george-orwell.org)
By amending the commandment to only forbid sheets, the pigs are able to raise their own status while keeping the other animals suppressed, and Squealer appeals to fear of Jones to keep them from complaining. His quick backtrack against the comfort of the beds shows that he was dangerously close to admitting how much the pigs are taking advantage of the other animals. By the end of the story, Napoleon has eliminated all the commandments except one, which has been amended: "All animals are equal, but some animals are more equal than others." This allows Napoleon to mold himself into the role of a human, becoming the ruler of the farm, entirely against the original meaning of Old Major's philosophy.