At the beginning of chapter II, the author states that "Snowball was a more vivacious character than Napoleon, quicker in speech and more inventive," and many of the early slogans can be attributed to him. For example, it is Snowball that paints and reads out the seven commandments that become the basis for most of the slogans.

The seven commandments are as follows:

1. Whatever goes upon two legs is an enemy.

2. Whatever goes upon four legs, or has wings, is a friend.

3. No animal shall wear clothes.

4. No animal shall sleep in a bed.

5. No animal shall drink alcohol.

6. No animal shall kill any other animal.

7. All animals are equal.

When the animals struggle to learn the commandments by heart, Snowball condenses them into the much easier to remember "Four legs good. Two legs bad."

In the end, Napoleon, who doesn't seem have the same intelligence as Snowball and therefore the ability to control the animals through rhetoric alone, chases Snowball off the farm and starts to lead in a more brutal manner.

In the final chapters, Napoleon's ideas seem nothing more than a twist on Snowball's ideas and he slowly changes the seven commandments to fit his own lifestyle. For example, after Napoleon and the other pigs get drunk, Napoleon changes "No animal shall drink alcohol" to "No animals shall drink alcohol to excess." After Napoleon kills animals who he says are traitors, he changes "No animal shall kill any other animal" to "No animal shall kill any other animal without cause."

By the end of the book, the seven commandments have been reduced to one line. "All animals are equal, but some are more equal than others."

During the conflict about the first windmill, it is clear that Napoleon only wants to shut off support for Snowball so he can continue his movement towards dictatorship. Because of this, he has no real plan, just the blind support of the sheep and vague promises of plenty in the future. While Snowball's vision is of machine-assisted farm life, with a reduced need for manual labor, Napoleon needs the animals to be overworked so they can't think about rebelling against him as they did against Farmer Jones.

...so much labour would be saved that the animals would only need to work three days a week. Napoleon... argued that the great need of the moment was to increase food production, and that if they wasted time on the windmill they would all starve to death. The animals formed themselves into two factions under the slogan, 'Vote for Snowball and the three-day week' and 'Vote for Napoleon and the full manger.'
(Orwell, Animal Farm, msxnet.org)

The slogans themselves betray the real attitudes of the two pigs. Snowball wants to use human technology to create a farm on which the animals can subsist for themselves, without ever needing to interact with humans, and so he points out the real results of building the windmill. Napoleon knows that Snowball's plan makes sense, and so his slogan is simply the empty promise of more food if the animals work the farm itself instead of building the windmill. Napoleon's slogan has nothing behind it; his words are empty, just as Snowball's are substantive.