The aim of an adversarial court system is to get at the truth by having the people on each side working hard to expose those bits of the truth that suit their goals. The system is supposed to get at the truth, and that doesn't necessarily require that all the people involved are primarily trying to get at the truth. It may even work best when they aren't.
Similarly: buyers and sellers in a market needn't individually be aiming to arrive at an efficient or socially beneficial outcome; voters in a democracy needn't individually be aiming to elect someone who will be best for everyone's interests; employees of a company needn't all be concerned solely with the company's success. The trick is to design the system so that even when individual people are motivated by self-interest the aggregate effect is a good one.
Of course, none of these systems works perfectly in practice, and sometimes that's because some individual's self-interest ends up having too much influence on the outcome. Some or all of the systems might want changing to encourage participants to act less self-interested somehow. But I think it's just an error to say "Ugh, those people are acting in their own interests and not pursuing the top-level goal of the system" when the system is designed to get individuals' pursuit of their own interests to work towards that top-level goal.
Your right about the system being designed a certain way and that's how it should work. The problem is that the state has so many more resources, and if you add flat out lying to the mix, the system breaks down. I'm of the opinion that since the state has the burden of proof and virtually unlimited resources that they should also be striving for the truth above all else. When it becomes more about convictions and less about justice, the system will fail to the detriment of all of society.
It is more important that innocence be protected than it is that guilt be punished, for guilt and crimes are so frequent in this world that they cannot all be punished. But if innocence itself is brought to the bar and condemned, perhaps to die, then the citizen will say, “whether I do good or whether I do evil is immaterial, for innocence itself is no protection,” and if such an idea as that were to take hold in the mind of the citizen that would be the end of security whatsoever. -John Adams
buyers and sellers in a market needn't individually be aiming to arrive at an efficient or socially beneficial outcome
Yet we have regulation because we've seen sellers destroy the environment and take advantage of buyers left and right.
voters in a democracy needn't individually be aiming to elect someone who will be best for everyone's interests
Yet Congress has shone time and again that corruption and cronyism are at it's heart, even if it sacrifices what is good for the people, the economy, or the government. (I don't think the system is even working right now, but that doesn't mean it won't in the future; the US has gone through times lime this before.)
employees of a company needn't all be concerned solely with the company's success
But what happens when employees only focus on their own reward? Companies like that become intolerable places to work at that are hugely inefficient, generally surviving only by cannibalizing itself or by simply leveraging its mass in a pseudo-illegal way). The corporate system is designed for everybody to be doing what is best for the company (which might not always be profits), but that breaks down, too, when everybody starts pursuing their own agenda to the exclusion of anything else.
Systems can take a certain amount of perturbation and survive, but, just like Stuxnet and the centrifuges, if you introduce too much disorder in a system, it will break down. In human society, it seems selfishness, that drive to take care of myself regardless of what it means to anybody else, is often the root cause of that (it certainly is in all the above cases).
It's too bad we can't be a little more communally-oriented (without needing to live in the forest in a VW and not take baths ;). Who wants to do a sun-dance with me to find some extra pollen for the hive?
Did you perhaps miss the bit where I said "Of course, none of these systems works perfectly in practice, and sometimes that's because some individual's self-interest ends up having too much influence on the outcome. Some or all of the systems might want changing to encourage participants to act less self-interested somehow." ?
I wasn't saying "there's never anything wrong with selfishness" or "systems that try to make selfishness produce results that benefit everyone never get exploited" or anything of the kind. Just pointing out that "look, people are being self-interested rather than aiming to serve the greater good" isn't on its own a good objection.
I also wasn't arguing that there should (in any of these domains) be no regulation. There should be, and as it happens there is. Perhaps there should be more. That's an entirely separate question from whether a basically-adversarial system in which all the lawyers are out to win is a good thing.
So far as I know, it's an open question whether justice is best served by a purely adversarial system in which everyone argues for a particular outcome, or a purely investigative system in which no one is supposed to be on one side rather than another, or a basically adversarial system with a bunch of rules that aim to take some of the edge off (which is what we have now), or some other intermediate thing. It's not the sort of question you can resolve by saying "You can't do that -- it means everyone just cares about winning!" or "You can't do that -- it relies on people ignoring their own interests!".
Similarly: buyers and sellers in a market needn't individually be aiming to arrive at an efficient or socially beneficial outcome; voters in a democracy needn't individually be aiming to elect someone who will be best for everyone's interests; employees of a company needn't all be concerned solely with the company's success. The trick is to design the system so that even when individual people are motivated by self-interest the aggregate effect is a good one.
Of course, none of these systems works perfectly in practice, and sometimes that's because some individual's self-interest ends up having too much influence on the outcome. Some or all of the systems might want changing to encourage participants to act less self-interested somehow. But I think it's just an error to say "Ugh, those people are acting in their own interests and not pursuing the top-level goal of the system" when the system is designed to get individuals' pursuit of their own interests to work towards that top-level goal.