Defining the scope of a "social contract" involves trying to discount and avoid personal preferences, biases and prejudices. Rawls recommends a detached advocate of the "contract" to place himself/herself behind a veil of ignorance.
Step behind this veil. Imagine that you are ignorant of yourself, your natural abilities and social position. Knowledge of personal racial, sex, national or other interests and commitments cannot then influence your judgement. You become . a rational, free, and morally equal being.
Is this the "real world"? In the real world
Rawls suggests that although assets/abilities are widely, naturally, variably distributed/accumulated with sex, race, cultur differences nonetheless behind the veil, the only safe principles are fair ones. Rationality governs our choice of basic social principles. Behind the veil and in our ignorance, we don't know if we will be the beneficiaries or victims of institutional or social bias. So therefore the highest minimum standards of justice in a society offer safe and fair principles.
