So spare a thought for the members of a parliamentary committee who have to come to grips with a complex and important topic that affects all of us and is fraught with powerful emotions and deep divisions.

In Victoria, the Legal and Social Issues Committee of the Upper House is examining end-of-life choices, including voluntary euthanasia or voluntary assisted dying.

They (or their staff) have to wade through about 1000 written submissions and digest the evidence put forward in more than a dozen public hearings.

Many of the submissions are written by skilled advocates who may well be experts on the topic, but whose purpose is not to present an objective and thorough analysis. It is to argue a case.

So the committee, like a judge, has to test the evidence to see what is factual, what is misguided and even what is deliberately misleading or false.

They will be well aware of common techniques used by advocates. Let us have a quick look at four of them.

One such technique is simply not including an uncomfortable fact. For example, the Australian Medical Association opposes voluntary euthanasia because it considers the role of a doctor to be a healer. And it is. But it is not the only role. A doctor's duty is also to relieve suffering, and sometimes the only, or most expeditious, way to relieve suffering is to help a patient to die.

An uncomfortable fact is that in Australia doctors do in fact intentionally help people to die. As reported in The Medical Journal of Australia, a survey in 2001 asked "Have you ever, for the purposes of relieving a patient's suffering, given drugs … in doses greater than those required to relieve symptoms, with the intention of hastening the patient's death?" Thirty-six per cent of the doctors surveyed said "yes".

A second common technique is advancing a half-truth as if it is all that needs to be said. Opponents of voluntary euthanasia frequently state baldly that, in 2005, doctors in the Netherlands hastened the deaths of 550 people without their consent. The clear implication is that evil doctors are killing people prematurely and against their will, and that this is the result of having legal voluntary euthanasia.

This is deliberately misleading.

The practice we are talking about here is "non-voluntary euthanasia", where a doctor helps a patient to die without an explicit request. It is not performed under any voluntary euthanasia law. Those laws all require an explicit and written request from the person seeking a doctor's help to die. Non-voluntary euthanasia is in fact illegal. However, as The British Journal of General Practice reported in April 2010, in an article about the Dutch euthanasia act, in such cases there have been no prosecutions against doctors in the Netherlands. The patients were typically very close to death, mentally incompetent and usually there had been an earlier discussion about hastening death with them and/or their relatives. Further, simply quoting the absolute figures for only one year is statistical sleight-of-hand. It is misleading in at least two ways – it ignores the trend and the significance of the numbers.

Not only is the number of non-voluntary euthanasia deaths as a proportion of all deaths falling in the Netherlands, but they are a minuscule fraction of the total number of deaths. They represented 0.8 per cent of all deaths in the Netherlands in 1990, 0.4 per cent in 2005 and 0.2 per cent in 2010. So a voluntary euthanasia law is not the cause of non-voluntary euthanasia.

The Australian survey in 2001 mentioned above also demonstrated that Australian doctors who helped their patients to die often did so without an explicit request. While the Dutch are candid enough to acknowledge the practice, and are open and accountable, our Australian doctors have to carry out such compassionate acts covertly.

A third, all-too-common, tactic is to conjure up the threat of dire consequences if there is any change to the law. Perhaps the most frequent argument put up against voluntary assisted dying is that the vulnerable – for example, the old, the sick, the poor, and the uneducated – are threatened and that the safeguards cannot work.

For example, the Australian Christian Lobby says bluntly in its submission to the Victorian enquiry: "No euthanasia law can provide adequate protection for the vulnerable." Later in its submission it states; "One serious concern about euthanasia is that it may create an environment in which the elderly are vulnerable to abuse". "Can" or "may"? What is the empirical evidence?

The Western world has extensive practical experience of the operation of legal assisted dying. It is 31 years since a court ruling in the Netherlands made voluntary euthanasia legal there, almost 20 years since a law was passed in Oregon, and 13 years since a law was passed in Belgium. Reputable independent authorities, such as the Canadian Royal Society and the Australian think-tank Australia 21, have studied this experience. They concluded that the safeguards could and did work.

What I find most surprising about the Australian Christian Lobby's contrary conclusion is that they do not support it with evidence of even one instance of abuse. I would have thought that any such instance would have been highlighted. The reality is that good public policy should be based on hard evidence rather than scaremongering.

Finally, there is the technique of attention-grabbing claims that are simply not true. On the recent Q&A ABC TV program about voluntary assisted dying, a member of the audience confronted Andrew Denton and claimed that an official Dutch report showed that 550 babies had been killed. After the show, the audience member admitted that he could not substantiate the figure. There is a related claim on a Catholic website, but again there is no evidence whatsoever for such a shocking but untrue assertion. As Denton said, "there was no evidence for the claim in the annual reports published by the Dutch Euthanasia Review Committee".

How will the Victorian parliamentary committee know when they are being told "the truth, the whole truth and nothing but the truth"?

Their difficult job is not something I envy.

But all Australians who support voluntary euthanasia or voluntary assisted dying will be eagerly awaiting their findings.

Emeritus professor of history and politics at Griffith University, Ross Fitzgerald is the author of 38 books, including his memoir My name is Ross: An alcoholic's journey.