The BBC, wrote in a section titled "The Slippery Slope" on the "Religion & Ethics: Ethical Issues" page of www.bbc.co.uk (accessed Aug. 10, 2009):
"Many people worry that if voluntary euthanasia were to become legal, it would not be long before involuntary euthanasia would start to happen…
This is called the slippery slope argument. In general form it says that if we allow something relatively harmless today, we may start a trend that results in something currently unthinkable becoming accepted.
Those who oppose this argument say that properly drafted legislation can draw a firm barrier across the slippery slope."
Would legalizing voluntary euthanasia and assisted suicide create a slippery slope to involuntary euthanasia?
Edmund D. Pelligrino, MD, Professor Emeritus of Medicine and Medical Ethics at Georgetown University, wrote in the chapter titled "The False Promise of Beneficent Killing" in Regulating How We Die: The Ethical, Medical, and Legal Issues Surrounding Physician-Assisted Suicide, edited by Linda L. Emanuel in 1998:
"In a society as obsessed with the costs of health care and the principle of utility, the dangers of the slippery slope... are far from fantasy...
Assisted suicide is a half-way house, a stop on the way to other forms of direct euthanasia, for example, for incompetent patients by advance directive or suicide in the elderly. So, too, is voluntary euthanasia a half-way house to involuntary and nonvoluntary euthanasia. If terminating life is a benefit, the reasoning goes, why should euthanasia be limited only to those who can give consent? Why need we ask for consent?"
David Souter, LLB, Associate Justice of the US Supreme Court at the time of the quote, wrote in his June 26, 1997 concurring opinion in Washington v. Glucksberg:
"[Physicians] have compassion, to the wishes of a patient, whether the patient were technically quite responsible or not... Physicians and their hospitals, have their own financial incentives, too, in this new age of managed care. Whether acting from compassion or under some other influence, a physician who would provide a drug for a patient to administer might well go the further step of administering the drug himself; so, the barrier between assisted suicide and euthanasia could become porous, and the line between voluntary and involuntary euthanasia as well. The case for the slippery slope is fairly made out here... because there is a plausible case that the right claimed would not be readily containable by reference to facts about the mind that are matters of difficult judgment, or by gatekeepers who are subject to temptation, noble or not."
Herbert Hendin, MD, Professor in the Department of Psychiatry and Behavioral Sciences at New York Medical College, wrote in his article "The Slippery Slope: The Dutch Example," that appeared in the Fall 1996 issue of the Duquesne Law Review:
"Once physician-assisted suicide is legally permitted for patients designated as terminally ill, the gradual extension of the practice to ever-widening groups of patients has been referred to as the slippery slope. The Netherlands, where doctors are able to practice euthanasia as long as they follow certain established guidelines, provides an empirical example of what the slippery slope means in actual practice.
Over the past two decades, Dutch law and Dutch medicine have evolved from accepting assisted suicide to accepting euthanasia, and from euthanasia for terminally ill patients to euthanasia for chronically ill individuals. It then evolved from euthanasia for physical illness to euthanasia for psychological distress. Finally, it evolved from voluntary euthanasia to the practice and conditional acceptance of non-voluntary and involuntary euthanasia. Once the Dutch permitted assisted suicide, it was not possible medically, legally, or morally to deny more active medical help such as euthanasia to individuals who could not effect their own deaths.
Although involuntary euthanasia has not been legally sanctioned by the Dutch, it has increasingly been justified or excused as necessary by the need to relieve suffering patients who are not competent to choose a course of action for themselves.
The inability to regulate euthanasia within established rules is even more slippery. Virtually every guideline established by the Dutch (whether it be a voluntary, well-considered, persistent request; intolerable suffering that cannot be relieved; consultation; or the reporting of cases) has failed to protect patients or has been modified or violated with impunity."
Robert M. Walker, MD, Associate Professor in the Department of Internal Medicine in the Division of Medical Ethics and Humanities at the University of South Florida College of Medicine, wrote in a Jan./Feb. 2001 Cancer Control article titled "Physician-Assisted Suicide: The Legal Slippery Slope":
"The current legal system allows the possibility of a legal slippery slope in moving from PAS [physician-assisted suicide] to voluntary euthanasia to nonvoluntary euthanasia. As with all valid slippery slope arguments, the conclusion is one of probability. There is no guarantee that our case law will move in this direction; this paper only points out its potential to do so. This potential is to some extent mitigated by the US Supreme Court’s ruling that there is no constitutional basis for a right to assisted suicide, the Court’s emphasis on improving palliative care, and its assertion that states have an interest in 'preventing voluntary and perhaps even involuntary euthanasia.' Despite this, the potential for extending PAS to incapacitated patients remains. At a minimum, this scenario of case law extension of PAS to incapacitated patients should at least give pause to true advocates of patient choice. It should prompt them to reconsider the wisdom of continued efforts to legalize PAS, since doing so expands the potential for future legal decisions that will end life based not on patient choice but on the choice of others."
Wesley J. Smith, JD, Senior Fellow in Human Rights and Bioethics at the Discovery Institute, wrote in his 2000 book Culture of Death: The Assault on Medical Ethics in America:
"Oregon is sliding down the same slippery slope as did the Netherlands. Once killing is redefined from bad to good, the protective guidelines for assisted suicide, which advocates assure us will keep the practice of hastening death corralled, are also quickly redefined, at least in practice, as obstacles to be overcome. Then they are attacked, ignored, or reinterpreted, while potential violations go essentially uninvestigated - to the point where they eventually become irrelevant."
R.G. Frey, DPhil, Professor of Philosophy at Bowling Green State University, wrote in a chapter titled "The Fear of a Slippery Slope," that appeared in his 1998 book Euthanasia and Physician-Assisted Suicide: For and Against, coauthored with Gerald Dworkin and Sissela Bok:
"Especially with regard to taking life, slippery slope arguments have long been a feature of the ethical landscape, used to question the moral permissibility of all kinds of acts... The situation is not unlike that of a doomsday cult that predicts time and again the end of the world, only for followers to discover the next day that things are pretty much as they were...
We need the evidence that shows that horrible slope consequences are likely to occur. The mere possibility that such consequences might occur, as noted earlier, does not constitute such evidence."
In Compassion in Dying v. State of Washington (decided Mar. 6, 1996), the US Court of Appeals for the Ninth Circuit, in a decision written by Circuit Judge Stephen Reinhardt, held that:
"Known as a slippery slope argument or what one commentator has called the 'thin edge of the wedge' argument, the opponents of assisted-suicide conjure up a parade of horribles and insist that the only way to halt the downward spiral is to stop it before it starts...
This same nihilistic argument can be offered against any constitutionally-protected right or interest. Both before and after women were found to have a right to have an abortion, critics contended that legalizing that medical procedure would lead to its widespread use as a substitute for other forms of birth control or as a means of racial genocide. Inflammatory contentions regarding ways in which the recognition of the right would lead to the ruination of the country did not, however, deter the Supreme Court from first recognizing and then two decades later reaffirming a constitutionally-protected liberty interest in terminating an unwanted pregnancy. In fact, the Court has never refused to recognize a substantive due process liberty right or interest merely because there were difficulties in determining when and how to limit its exercise or because others might someday attempt to use it improperly.
Recognition of any right creates the possibility of abuse. The slippery slope fears of Roe's [Roe v. Wade] opponents have, of course, not materialized. The legalization of abortion has not undermined our commitment to life generally; nor, as some predicted, has it led to widespread infanticide. Similarly, there is no reason to believe that legalizing assisted suicide will lead to the horrific consequences its opponents suggest."
Derek Humphry, President of the Euthanasia & Guidance Organization (ERGO), wrote in an article titled "The Case for Assisted Suicide and Active Voluntary Euthanasia" on near-death.com (last updated on June 11, 2006):
"This [slippery slope] argument is singularly implausible if one who makes it means that there is a logical connection between the killings in question such that one who endorses the first cannot without inconsistency refuse to endorse the last. The fact that in one case a person is killed in his own interest because he requests it, whereas in the other a person is killed in the interest of others without (or contrary to) his consent, is surely a morally relevant difference.
Since this is so, the question 'How can we draw the line?' should not perplex one for long. No one thinks that making killing in self-defense an exception to criminal homicide starts one on a slippery slope which logically must end in the abolition of the crime of murder; no one should think the same about legalizing voluntary euthanasia. A more common and plausible way of understanding the objection is to take it as alleging an empirical connection between the killings in question. If, however, the claim is an empirical one, it stands in need of evidence. What is the evidence that a policy of allowing death on request, begun in good faith and motivated by compassion, will lead to unwanted killings?
Two items of evidence are commonly alleged. The first is the Nazi experience. However, there is no parity between the cases; all they have in common is the name euthanasia. In these cases, the name stands for quite different policies. The Nazi program of euthanasia was neither voluntary nor based on compassion; it was, rather, motivated by the desire to remove useless eaters and preserve the purity of the Volk, and hence was the result of a vicious and racist ideology already firmly in place, not the unwanted and unexpected upshot of an intrinsically desirable social reform.
The second, which is currently attracting the most attention, is the Netherlands experience. In the Netherlands we have a living laboratory in which the euthanasia experiment in being conducted, and it is claimed that active non-voluntary and involuntary euthanasia are openly practiced there, exactly as predicted by the slippery slope argument. But the claim of the open and common practice of involuntary euthanasia has been often repeated but has never been substantiated, and indeed has been repeatedly challenged."