It's just one of those things about truth.
Even in such a case, it may be hard to find the truth. But it's much harder in a case of personal interest, such as breach of contract or property claim and, of course, police cases, where parties may know, but be tempted to deny or airbrush, the truth.
When money or freedom is at stake, the truth is tradeable - and it may be no better if lawyers are engaged.
It's not the job of lawyers or police to know the truth, but to present the case, with evidence on oath.
Wherever two or more are together, they may disagree, and eventually seek help to settle their differences, in some sort of contest or electoral process.
They may engage experts in PR or other contemporary science, who raise the stakes and increase the pressure on truth.
So it is in politics - and we see the issue presented as a matter of "equality" in marriage - which it's simply not at all, but some believe it and others can be persuaded, and many will be drawn to the cause.
People don't even need to know what they think.
A little confusion goes a long way, sells newspapers and splits the vote.
Debate about alcohol and drugs will go on forever, but most of us know already, or don't want to know.
Publicity and media obscure the truth.
Personal or political interest may guide the so-called conscience vote.
In the law of all places, truth should be revered, but it doesn't always win. It's for the jury to sort the facts, and the judge to apply the law.
Does anyone know the truth? Even when it's there to be seen, we don't know how it will turn out at trial.
Justice is uncertain, and may be delayed and expensive.
We try to negotiate settlement, and avoid the court; but there's temptation to conceal facts; to misquote or take words out of context; to engage in tricks of debate and ever the threat of costs.
Expediency is the unseen elephant treading heavily on truth.
The outcome may be imperfect or even unjust, but better than the danger and delay of litigation.
I abhor expediency but justice gets lost in a professional contest.
John Tripe is principal with the Wanganui legal firm of Jack Riddet Tripe