Social justice is not an abstract concept that arises out of thin air in people's minds, but the development of social development that comes into being with the emergence of society.Under different historical conditions, people's understanding of social justice is different. Engels once pointed out that the fairness of the Greeks and Romans believed that slavery was fair.The fairness of the bourgeoisie in 1789 demanded the abolition of feudalism because it was said to be unfair
the concept of permanent fairness varied not only according to local conditions, but even from person to person.
Social justice is historical