Chapter 1
Man is the only creature that consumes without producing.

EXPLANATION: Before the ambitious pig Napoleon rules over the animals with an iron hoof, the non-human denizens of Animal Farm were led by Old Major, an aging boar. Old Major teaches the animals about the inequalities between humans and animals on the farm, pointing out that the animals have to do work on the farm while the humans make all the profit and enjoy the fruits of the work. It's like Farmer Jones snatches the animals' paycheck before they can cash it in at the bank and use it for food and rent.

Man serves the interests of no creature except himself.

EXPLANATION: Major emphasizes that humans can't be trusted. After all, they only care about themselves, so animals need to do the same. Humans and animals can never be friends. Harsh words for harsh masters.

Let's face it: our lives are miserable, laborious, and short.

EXPLANATION: This line from his "I Literally Had a Dream" speech lays out the principal problem of the animals' lives: the humans take advantage of them, reaping all the benefits of the animals' labor and slaughtering them when they're no longer producing.

All men are enemies. All animals are comrades

EXPLANATION: The term comrade simply means friend, mate or ally. Its use suggests equality. Rather than using terms such as sir, madam, lord, lady, king or queen, which relate to class or status, the animals are now simply comrades and share everything equally.

Comments: The term is closely related to the Communist revolution in Russia where the leaders referred to each other as comrades in their struggle to remake Russia into a Communist state like the one first envisioned by Karl Marx.

Chapter 3 - “Four legs good, two legs bad.”

EXPLANATION: Four legs good, two legs bad comes from the speech made by Old Major in the beginning of the book that is one of the principles of the theory of animalism that is at the heart of the rebellion.  Old Major is instructing the animals to never trust anything that walks on two legs, he, of course, is referring to man, who he says is evil.

Chapter 4 - The only good human being is a dead one.

EXPLANATION: This passage shows Orwell's ingenious plan to show that communism actually leads to authoritarianism, or a dictatorship, like Stalin and his successors. And what made Animal Farm so risky was that it was published while Orwell's native England was allies with Stalin. The book was revolutionary in a way that Snowball could only dream about.

Chapter 5

Several of them would have protested if they could have found the right arguments.

EXPLANATION: Thus, Orwell suggests that the other animals are not clever enough to argue against Napoleon's declarations. Throughout the novel, Orwell mentions the difficulty that most of the animals have in learning or remembering various things.