Chapter X jumps forward several years. Many of the animals who participated in the Rebellion have died — Jones himself has perished in an inebriates' home elsewhere in the county, and Boxer and nearly all the original participants are gone. The farm has grown more prosperous: two additional fields have been purchased from Mr. Pilkington, the windmill has been completed (used for milling corn rather than generating electricity as Snowball originally proposed), and a second windmill is under construction. Yet despite all this material progress, the ordinary animals' lives are no better than they were under Jones. Only the pigs and dogs live in comfort.
The chapter's central dramatic sequence unfolds rapidly. Squealer takes the sheep away for a week, ostensibly to teach them a new song. When the sheep return, Clover witnesses a sight that makes her blood run cold: Squealer walking upright on his hind legs, followed by the other pigs, and finally Napoleon himself — carrying a whip in his trotter. Before any animal can protest, the sheep burst into a deafening new chant: "Four legs good, two legs better!" The trained bleating drowns out any possibility of dissent, just as the sheep's earlier chant of "Four legs good, two legs bad" silenced debate in previous chapters.
Clover and Benjamin approach the barn wall where the Seven Commandments were once painted. All seven rules have been erased and replaced by a single maxim: "ALL ANIMALS ARE EQUAL BUT SOME ANIMALS ARE MORE EQUAL THAN OTHERS." This paradoxical slogan — one of the most famous lines in English literature — represents the ultimate corruption of Old Major's principles. Equality itself has been redefined to justify permanent hierarchy.
The novel's devastating conclusion follows. Napoleon invites a delegation of neighboring human farmers to inspect the farm. At a dinner party in the farmhouse, Mr. Pilkington delivers a toast praising the pigs for extracting more labor from their animals for less food than any farm in the county. Napoleon responds by announcing sweeping changes: the farm will revert to its original name of "The Manor Farm," the word "comrade" is abolished, the custom of marching past Old Major's skull is eliminated, and even the hoof-and-horn flag will be replaced by a plain green banner. The revolution, in both name and substance, is formally erased.
The final scene is Orwell's masterpiece of political allegory. The animals creep back to the farmhouse window and peer inside at a card game between pigs and humans. A quarrel erupts — Napoleon and Pilkington have both played an ace of spades simultaneously. As the creatures outside gaze through the window, they look from pig to man, and from man to pig, and from pig to man again — but already it is impossible to say which is which. The oppressed cannot distinguish their new masters from their old ones. The revolution has come full circle.