Benjamin is the donkey in the story, he is very cynical about the change in power at Animal Farm. He does not believe that things will get better with the revolution, in fact, he remains neutral when the struggle for power between Napoleon and Snowball erupts.
Although Benjamin understands what is going on at Animal Farm, he has no desire to oppose the pigs. He realizes that the revolt will not produce the utopia that was promised, he knows that life will be more or less the same revolt or not. He does not have his hopes artifically raised with the belief that there will be a fair and equal existence on Animal Farm for all animals.
Benjamin, as the oldest animal on the farm, is wise, and therefore, he is not shocked by anything that he sees, including the executions that take place at the hands of Napoleon.
The only time Benjamin is moved to react, to use his knowledge for good, is when he reads the side of the truck that comes to take boxer, his friend, away. However, after he realizes the the truck is taking him to the slaughterhouse, it is too late to stop the process.
Benjamin's knowledge gives power only to him, he does not become active in trying to change anything on the farm. The only thing that Benjamin derives from his knowledge is the power of knowing that there is no hope so therefore, he cannot be disappointed.