In chapter 5, what maxim does Boxer adopt?

In chapter five of the novella, Napoleon successfully usurps power and has his nine ferocious dogs chase Snowball off the farm. Once Snowball is driven from the farm, Napoleon announces that there will be no more Sunday meetings and declares that a committee of pigs will preside over policy issues. The other animals are initially suspicious and do not know how to react to Napoleon's new policies but are intimidated by his aggressive, menacing dogs. Napoleon then sends Squealer out to smooth things over with the animals and persuade them that he will make a good leader. After Squealer diminishes Snowball's accomplishments and sacrifices during the Battle of the Cowshed, Boxer thinks things over and adopts the new maxim of "Napoleon is always right," in addition to his private motto of "I will work harder" (Orwell, 19). Boxer's inability to perceive Napoleon as a hostile tyrant and his creation of a flattering new motto that praises Napoleon emphasizes his ignorance and optimistic naivety.

In Chapter Five, Boxer adopts the following maxim:

Napoleon is always right.

To put this into context, Napoleon has just put an end to the Sunday morning meetings in which the animals come together to discuss what is best for the farm. To support Napoleon's decision, Squealer says that Napoleon has taken on this "deep and heavy responsibility" because he is worried that the animals might make mistakes about their governance. To support this idea, Squealer uses the example of Snowball, a traitor the animals once trusted. Squealer also suggests that if the animals make wrong decisions about their future, then it is likely that Jones will return.
In response, Boxer accepts that Napoleon is always right. He is so afraid that Mr. Jones might return that he is prepared to put his future into Napoleon's hands. Squealer's powers of persuasion have, therefore, proved to be effective, enabling Napoleon's rise to absolute power.