In Italian courts, if I remember correctly, it is presumed that defendants would lie on their own behalf. If true, this strikes me as an apt, rather than cynical, reading of human nature.
In the United States, legal proceedings find footing in the promise from those testifying that they will tell "the whole truth and nothing but the truth." Failure to do so constitutes perjury, a punishable offense.
Given the hearings before Congress and the courts -- hearings about banking, stock market, insurance and other complex malfeasances that leave the rest of us financially gasping -- I wonder if it would be possible:
When a person testifying claims to "have no recollection," and when those questioning this person have reason to doubt his or her statement, would it be possible to ask that the person undergo a lie detector test? "Excuse me, sir, but would you please report to the lie detector department ... it's down the hall and to your left."
Lie detector tests are intrusive and not always reliable, but the object of administering the test would not be to say what the truth of the matter was; the object would be to determine if the person were a liar ... and hence a person whose "whole truth" was something shy of the truth ... and hence that his testimony could be doubted ... and further investigation might be warranted.
I doubt that Congress would have the nerve to insert a lie-detector provision into its precepts for hearings (who is his right mind, especially all those lawyers, would want to be hoist by his own petard?), but the idea that such a clause might be inserted and exercised, well, it appeals to me.
Not as a matter of finding out the truth of the matter at hand.
Just as a means of helping to verify that the "whole truth and nothing but the truth" was within the witness' willing boundaries.
OK ... it's a wet dream. But everyone has those once in a while.