https://en.wikipedia.org/wiki/Veil_of_ignorance
The "veil of ignorance" is a method of determining the morality of political issues proposed in 1971 by American philosopher John Rawls in his "original position" political philosophy. It is based upon the following thought experiment: people making political decisions imagine that they know nothing about the particular talents, abilities, tastes, social class, and positions they will have within a social order. When such parties are selecting the principles for distribution of rights, positions, and resources in the society in which they will live, this "veil of ignorance" prevents them from knowing who will receive a given distribution of rights, positions, and resources in that society. For example, for a proposed society in which 50% of the population is kept in slavery, it follows that on entering the new society there is a 50% likelihood that the participant would be a slave. The idea is that parties subject to the veil of ignorance will make choices based upon moral considerations, since they will not be able to make choices based on their own self- or class-interest.
As Rawls put it, "no one knows his place in society, his class position or social status; nor does he know his fortune in the distribution of natural assets and abilities, his intelligence and strength, and the like".[1] The idea of the thought experiment is to render obsolete those personal considerations that are morally irrelevant to the justice or injustice of principles meant to allocate the benefits of social cooperation. The veil of ignorance is part of a long tradition of thinking in terms of a social contract that includes the writings of Immanuel Kant, Thomas Hobbes, John Locke, Jean Jacques Rousseau, and Thomas Jefferson.