Which principle ensures that similar cases receive similar treatment under the law?

The principle that ensures similar cases receive similar treatment under the law is known as equal protection. This concept is rooted in the idea that all individuals should be treated the same under similar circumstances, promoting fairness and equality in the legal system. Equal protection is most commonly associated with the Fourteenth Amendment to the U.S. Constitution, which mandates that no state shall deny to any person within its jurisdiction "the equal protection of the laws."

This principle is essential for maintaining a just legal system, as it prevents arbitrary discrimination and promotes uniformity in the application of laws. For example, if two individuals commit the same crime under the same conditions, the legal consequences they face should be similarly aligned to uphold the equal protection standard. This ensures that justice is not only administered fairly but is also perceived as fair by the public.

In contrast, judicial review pertains to the power of courts to assess whether a law is constitutional, due process focuses on the legal safeguards that protect individuals' rights, and separation of powers refers to the distribution of authority among the legislative, executive, and judicial branches of government. While these concepts are all significant in governance and law, they do not specifically address the treatment of similar cases in the same manner as equal protection does.