"Now what is the difference between the two? How does one determine whether a law is just or unjust? A just law is a manmade code that squares with the moral law or the law of God. An unjust law is a code that is out of harmony with the moral law. To put it in terms of St. Thomas Aquinas: An unjust law is a human law that is not rooted in eternal law and natural law. Any law that uplifts human personality is just. Any law that degrades human personality is unjust. All segregation statutes are unjust because segregation distorts the soul and and damages the personality. It gives the segregator a false sense of superiority and the segregated a false sense of inferiority. Segregation, to use the terminology of the Jewish philosopher Martin Buber, substitutes an “I-it” relationship for an “I-thou” relationship and ends up relegating persons to the status of things. Hence segregation is not only politically, economically, and sociologically unsound, it is morally wrong and sinful.

Let us consider a more concrete example of just and unjust laws. An unjust law is a code that a numerical or power majority group compels a minority group to obey, but does not make binding on itself. This is difference made legal. By the same token, a just law is a code that a majority compels a minority to follow and that it is willing to follow itself. This is sameness made legal”

Letter From Birmingham Jail pg. 208