You are naive in assuming they want to find the truth.
The reality is that each side wants to win, thats it. The truth is irrelevant for them.
As for the judges. Is a job. Their career advancement is related to politics, not wisdom, not true nor justice. A political incorrect decision affects them more than a wrong decision. As long as they can write something that justifies their decisions, irrelevant if its true or not, they are happy.
There are at least two fundamental problems with any legal proceeding. The first is how adversarial legal argument is structured. Both sides, defendant vs. plaintiff/prosecution, argue from their <i>a priori</i> conclusion and thus try to ignore, discount, obscure or reject information that doesn't support their case. It's a very unscientific approach to determining truth and it often leads to injustice.
There is another a fundamental and profound fact about any legal proceeding that is rarely understood and very often obscured, which is that the point of the enterprise is to determine if what is at issue is <i>legal</i>, NOT whether it is "right" or "wrong." Legality is the ONLY thing that matters as far as the court is concerned; "right" & "wrong" is left for the legislature.
That said, it is an insufficiently known, albeit controversial, fact that a jury has the sovereign right and de facto power to determine, if it so decides, that the law itself is in the wrong and that the defendant is therefor not guilty or liable. This is known a "jury nullification," and will likely make the court VERY angry if it happens. It is, however, the citizenry's ultimate bulwark against unjust legislation, and has a long and mostly honorable history in law. (BTW, the "juror's oath" or a judge's instruction to decide only by the law is utterly unenforceable in an instance of jury nullification.)
@neldeeb : actually no, you can't divide by zero. In standard math it's not defined. A limit of something positive divided by zero is both inf (because if small positives) and -inf (small negatives) so there's no result. If that was the joke it's not a very good one.
I actually would like to serve on a jury. I think it would be interesting to see the legal system in action. Plus I get court leave at work so I would still be getting paid while serving.
The problem is that I have a PhD in Mechanical Eng. So the one time I made it to the box, I was quickly dismissed. The last thing they want is a person with a logical, rational mind, that can do physics. Especially in this case since it was about a car accident.