All people are biased, so how should we agree on a social contract to determine how the world should work?
We should imagine we sit behind a veil of ignorance that keeps us from knowing who we are and identifying with our personal circumstances.
By being ignorant of our circumstances, we can more objectively consider how societies should operate.
Primary principles
Liberty principle: ensure that people enjoy the maximum freedom posible without intruding on the liberty of others
Difference principle: guarantee that everyone has equal opportunity to prosper.
Fairness is the essence of justice.
Imagine you would have to choose the laws of society, but before choosing, you forgot everything about yourself.
Then you would place rules fair for everyone, not knowing where you would be
In choosing the rules behind the veil of ignorance, you would do your best to make sure no one was treated unfairly.
How to Make Fair Laws: John Rawls and the Veil of Ignorance - ThinkingAboutStuff
El Mundo de Sofía - Jostein Gaarder
Veil of Ignorance - Rawls