The Dying Barbarian, Greek, 2nd Century BC, Rome, Capitoline Museum

Ambrogio Lorenzetti, Bad Government, Palazzo Pubblico, Siena,  1340 A.D.
Justice is the constant and perpetual will to render to every man his due. Jurisprudence is the knowledge of divine and human affairs and knowledge of what is just and what is unjust. Iustitia est constans et perpetua voluntas ius suum cuique tribuens.  Iuris prudentia est divinarum atque humanarum rerum notitia, iusti atque iniusti scientia.    Justinian, Institutes 1.1 (533 A.D.) Justice:  Proper administration of the laws.  In jurisprudence the constant and perpetual disposition of legal matters or disputes to render to every man his due.  Black's Law Dictionary (6th edition, 1990)
Distributive Justice

The obligations of the community to the individual

 

 Commutative Justice

Obligations between persons that requires equality in all dealings between two persons.

 
A law student at the beginning of his studies should know from where "ius" comes.  Its name is taken from justice.  For, in the elegant words of Celsus, "ius" is the art of the good and the equitable.  Consequently we jurists are called priests because we cultivate justice,  and we seek knowledge of the good and the equitable.  We mark the difference between equitable and inequitable and determine what is licit and not licit.  Iuri operam daturum prius nosse oportet, unde nomen iuris descendat. est autem a iustitia appellatum: nam, ut eleganter Celsus definit, ius est ars boni et aequi. Cuius merito quis nos sacerdotes appellet: iustitiam namque colimus et boni et aequi notitiam profitemur, aequum ab iniquo separantes, licitum ab illicito discernentes.  Justinian, Digest 1.1.1.1 (533 A.D.)  Ulpian on the First Book of the Institutes (ca. 230 A.D.)  

 

What is justice but a tacit covenant of nature established for the aid of many.  Justice is not based on our statute but is a part of divine law and the bond of human society. Quid est iustitia, nisi naturae tacita conventio, in adiutorium multorum inventa. Iustitia non nostra constitutio, sed divina lex est, vinculum societatis humanae.

St. Martin of Braga, Formula honestae vitae (ca. 550 A.D.)

 
"Justice is the conformity of our actions and our will to the law."   Charles Bonaventure Marie Toullier (1752-1835)  Le droit civil français suivant l'ordre du code.