Based on the ideas I previously presented that 1) basing justice on the definitions of subjective quantities leads, at best, to unproductive debate and more commonly, to coercion and that 2) there is a class of goods which, by their nature, cannot be obtained by stealth, deception or coercion (virtues) and that this class of goods can be identified objectively, I submit the following as a tentative definition for justice:
Justice is that art which seeks to maximize the ability or opportunity of all concerned parties to seek virtue.
I'll give an example:
Suppose person A robs person B. Possible responses could be: do nothing; punish A arbitrarily (current American jurisprudence); force A to restore the goods to B; punish A arbitrarily and restore goods to B; allow B to exact revenge.... Which of these responses would maximize the ability of all parties to seek virtue? Nothing would leave B without the goods and likely angry and likely to do something unvirtuous. It would also enable A to continue to obtain goods in such a manner. Arbitrary punishment of A, perhaps incarceration, would certainly prevent unvirtuous behavior for a time, but likely not result in any increased capacity in A. It also does not begin to address B's feelings. Likely, the final answer would involve A restoring goods to B and perhaps some amount of punishment. The important point in this essay is not a particular answer, but the calculus of ability to seek virtue.
Notice that this approach to justice avoids the whole revenge thing and what A or B "deserves" and whose "rights" were or were not violated and whether those rights were natural or derived. It also avoids pejorative labels like "criminal" and avoids static judgements like "evil", "guilty" or "innocent".
Another example: Free transactions in the market. Economics theory only specifies THAT people set a value in the market, it does not delve into why. Justice based on virtue helps us understand. Producing needed products by labor and free agreements is a virtue. If the price is too low, then the seller can't continue seeking virtue in this manner - he would go out of business. If the price is too high, then the buyer has her resources consumed disproportionately and is thus impeded in her search for virtue that needed products would enable.
I would love to hear responses as to whether the calculus of virtue is clear or if you find it too muddy to apply.
I would also be happy to apply the calculus of virtue to any specific examples anyone would care to conjure up just to show the lines along which I am recommending people think about justice.