Justice is the lofty ideal and virtue of human society and has always been regarded as the essence and purpose of law. Justice can be divided into formal justice and substantive justice.

Formal justice, also known as procedural justice and procedural justice, means doing things strictly in accordance with legal provisions. It focuses on the justice of form and means;

Substantive justice only means that the law must conform to the needs of people. moral ideals and value demands, which focus on the justice of content and purpose. Since formal justice is reflected in the provisions of the law and has general and abstract characteristics, the specific implementation of rights and obligations may lead to substantive injustice in certain cases

The law must be as far as possible It reflects substantive justice and is consistent with people's political ideals and moral requirements. As Rousseau pointed out, "Law is an act of the general will" and "improvements and changes in the concept of social justice are often the pioneers of legal reform" (Bodenhay In the conflict between formal justice and substantive justice, people can break through lagging laws. Of course, the law is stable and cannot be changed overnight. This requires legislators to carefully weigh and reform the law at the appropriate time.