Reciprocity in deed: Productive, fully informed, warrantied, voluntary transfer, of demonstrated interests, free of imposition of costs upon the demonstrated interests of those external to the action.
Reciprocity in word: warrantied testimony sufficient to meet the demand for infallibility in the context in question.
The demand for reciprocity in word and deed is the deciding principle in contract law and all tort law. The difficulty is in accounting for the balance of reciprocities and irreciprocities.
Even political law is decided by reciprocity, but limited by proportionality, since it is proportionality that leads to defection against the political order.
The court does not rely on others’ agreement of a measure. Only in discovering a measure that tests for reciprocity. The reason being that one cannot agree to an irreciprocal contract, and the court will not enforce an irreciprocal contract – it will punish those for trying to construct one.
The practical result of incalculability is the court’s search for a means of decidability. It will sear for failure to perform. Failing failure to perform, It will search for dishonesty. Failing dishonesty it will search for failure of procedure (bullshit in m opinion). Failing procedure, it will request for voluntary settlement. Failing voluntary settlement the court renders “a mutually undesirable judgement”.
In the american system, which is completely adversarial, and where the law is largely created in court through adversarial competition(evidence) rather than administratively(research), the lawyers are rewarded for creating a narrative casting ordinary human error as incompetence and deceit, and ordinary human deceit as mere ordinary human error. The reason british (and some continental) systems are superior is that the continental system seeks the truth first, and the british system uses proxies before the court that inhibit ‘storytelling’. While the common law system is superior in every way, this failing of the american system requires reform – most likely on the british model. (Although, americans will resist it because it increases power distance.)
In the american system the jury trial is always available, but is a lottery, since the jury may also act on what it perceives as character: moral or immoral behavior and demeanor. (and it’s frightening how good juries are at their jobs.)
This is why there is value in the ‘unpredictability’ of jury trials, and in judicial discretion in settlements – to punish those who should settle and don’t. Hence the vast number of filed suits and the tiny number of juried cases – almost everything is settled, with law and court merely providing a venue where the threat of not resolving a dispute is worse than continuing the dispute.
This is why i repeat so frequently, the importance of testimony, since it is the means by which juries and courts decide marginal indifferences in the calculability of disputes of reciprocity.
So I think you’re confusing subjective (arbitrary and preferential) with the difficulty in conducting a FULL ACCOUNTING of “successes and failures to perform” (reciprocties and irreciprocities).