To expand on this, in case there are folks unfamiliar with Ayn Rands works. The consistent structure of her philosophy depends on
1. Metaphysics: Reality exists independently of consciousness ("A is A"), and humans can perceive it directly
2. Epistemology: Reason and logic are the only valid means of understanding reality
3. Ethics: Rational self-interest is the highest moral good
4. Politics: Individual rights (especially property rights) are absolute and capitalism is the only moral system
You can derive some of these from the others. Because reality is objective and we can know it through reason, we should always act only based on reason instead of emotion. Obviously our own happiness and self interest are proper moral aims. Doing that requires individual rights and capitalism.
This is internally consistent. The best part is that the book is fiction and no one comes out and says this in so many words. You need to “work it out” on the basis of the good guys believing this and the bad guys being collectivists. You feel smart when you work it out and you’re also more likely to accept it, because it wasn’t thrust on you. Of course the book throws subtlety to the wind around the end with a 100 page monologue.
As for the assumptions the philosophy rests on:
- Cognitive biases exist. Different people will perceive the same situation differently because of these biases. But objectivists will claim they don’t have any biases. I know at least two who told me they’re completely unbiased. (In fairness both have grown up since they told me this).
- Individual self interest will often conflicts with the interests of others. Game theory shows us that two prisoners pursuing “rational self interest” will lead to a worse collective outcome.
- Markets will often fail, spectacularly. And also, the right intervention can prevent them from failing. There are economics papers that discuss these failures, although in fairness many were published after Rand wrote her books.