If by unjust action I molest some one, whether in his person, his freedom, his property, or his honour, the wrong as regards =quality= remains the same. But with respect to =quantity= it may vary very much. This difference in the amount of wrong effected appears not to have been as yet investigated by moralists, although it is everywhere recognised in real life, because the censure passed is always proportional to the harm inflicted. So also with just actions, the right done is constant in quality, but not in quantity. To explain this better: he, who when dying of starvation steals a loaf, commits a wrong; but how small is this wrong in comparison with the act of an opulent proprietor, who, in whatever way, despoils a poor man of his last penny! Again: the rich person who pays his hired labourer, acts justly; but how insignificant is this piece of justice when contrasted with that of a penniless toiler, who voluntarily returns to its wealthy owner a purse of gold which he has found! The measure, however, of this striking difference in the quantity of justice, and injustice (the =quality= being always constant), is not direct and absolute, as on a graduated scale; it is indirect and relative, like the ratio of sines and tangents. I give therefore the following definition: the amount of injustice in my conduct varies as the amount of evil, which I thereby bring on another, divided by the amount of advantage, which I myself gain; and the amount of justice in my conduct varies as the amount of advantage, which injury done to another brings me, divided by the amount of harm which he thereby suffers.
We have further to notice a =double= form of injustice which is specifically different from the simple kind, be it never so great. This variety may be detected by the fact that the amount of indignation shown by disinterested witnesses, which is always proportional to the amount of wrong inflicted, never reaches the =maximum= except when it is present. We then see how the deed is loathed, as something revolting and heinous, as an _ἄγος_ (_i.e._, abomination), before which, as it were, the gods veil their faces. =Double= injustice occurs when some one, after definitely undertaking the obligation of protecting his friend, master, client, etc., in a special way, not only is guilty of non-fulfilment of that duty (which of itself would be injurious to the other, and therefore a wrong); but when, in addition, he turns round, and attacks the man, and strikes at the very spot which he promised to guard. Instances are: the appointed watch, or guide, who becomes an assassin; the trusted caretaker, who becomes a thief; the guardian, who robs his ward of her property; the lawyer, who prevaricates; the judge, who is corruptible; the adviser, who deliberately gives some fatal counsel. All such conduct is known by the name of =treachery=, and is viewed with abhorrence by the whole world. Hence Dante puts traitors in the lowest circle of Hell, where Satan himself is found (_Inferno_: xi, 61-60).