Though I said before that I intended to start in the Corpus Iuris Civilis series with the Digest before moving on to the Institutes, the composition of which was directed by the jurist, master of offices (magister officiorum), and minister of justice (quaestor) Tribonian (about whom I hope to have more to say later), I’ve changed my mind. What can I say? I suppose that, with Hippolytus, “my tongue swore, but my mind was still unpledged.” 1
I’m going to begin with the definitions at the commencement of the Institutes (Book I, titulus I, De justitia et iure), breaking them up into very small sections.
So, first: what is justice?
Justitia est constans et perpetua voluntas ius suum cuique tribuens.
“Justice is the constant and perpetual disposition granting to each person his right.”
So of “justice,” this abstracted concept, is predicated a “disposition,” voluntas. The term signifies will, willingness, inclination. Justice, then, consists in a will, a wish, a desire.
But this disposition is qualified in important ways. First, it is steadfast and enduring (constans et perpetua), not fickle and ever fluctuating. It is solid and predictable.
Next, it is a disposition necessarily finding fruition in action: note the participial modifier of voluntas, “bestowing” or “granting” (tribuens). Justice is a consistent-bestowing-disposition.
That action, that “granting,” has, in its turn, an object: ius–what is right, what is obligatory, what is due. Ius, then, encompasses both rights and duties. A person has a right to receive his ius, his due, and the other is obligated to give it to him. There is an etymological connection in Latin that is absent in English: the peculiar quality of the concept iustitia consists in a rendering of ius (for a discussion of the range of this term, see here).
Finally, justice is impartial, for it consists in rendering his due (ius suum) to each person (cuique), not just to some. For justice to obtain, each person’s ius, his due–whatever that may be–must be granted. 2