Catechism of the Catholic Church

Justice is the moral virtue that consists in the constant and firm will to give their due to God and neighbor. Justice toward God is called the "virtue of religion." Justice toward men disposes one to respect the rights of each and to establish in human relationships the harmony that promotes equity with regard to persons and to the common good. The just man, often mentioned in the Sacred Scriptures, is distinguished by habitual right thinking and the uprightness of his conduct toward his neighbor. "You shall not be partial to the poor or defer to the great, but in righteousness shall you judge your neighbor." "Masters, treat your slaves justly and fairly, knowing that you also have a Master in heaven." (2095, 2401)