The Slippery Slope II
Michael A. Gillette, Ph.D.

Now that the structure of the slippery slope argument has been made clear (in last month's newsletter), it is time to discuss the proper use of these arguments and the most effective responses to them. As explained, the basic strategy of a slippery slope argument is to show that a particular action or practice is morally unacceptable not necessarily because it is itself immoral, but because it will lead to other actions or practices which are immoral.

The discussion which prompted this examination of slippery slope arguments surrounded physician assisted suicide. One common argument in this area states that it may be perfectly justifiable to end the life of a terminally ill, suffering, competent patient who requests death. If we begin this practice, however, we will soon start killing people who are not terminally ill, or presently suffering. Worse yet, we will begin to make decisions for those who cannot decide for themselves. Ultimately, we will even overrule the stated preferences of incompetent patients who explicitly refuse euthanasia, and that would be immoral.

This is an example of a psychological slippery slope. If we really believe that patient's have the right to make their own choices, then the patient who is competent and wants to die is in a separate logical class than either the patient who cannot indicate desires or the patient who fails to have desires at all. Therefore, no logical connection between the competent patient and the incompetent patient exists, and allowing euthanasia for the first does not entail allowing euthanasia for the second. The argument maintains, however, that even absent this logical connection, allowing the competent patient to be euthanized will lead to abuse against those who lack competence.

By pointing out the distinction between a logical and a psychological slippery slope, the first major response to this type of argument becomes clear. In order for a psychological slippery slope to work, we must assume the worst in people. We must imagine that people are so unreflective and incapable of critical analysis that they will blindly slip down the slope from justified euthanasia to murder. In favor of this argument one might point to history and argue that people have done some horrendous things to each other in the past. Surely it is not hard to believe that such mistakes can happen again.

This attempt to save the slippery slope is weak, however. While it is true that human beings have often been cruel to each other, it is not necessarily the case that they have done this by accident. The fact that well meaning people can be led to immoral activity does not show that such will be the case in this area. One could equally well argue that by allowing people to kill in self-defense we open up the opportunity for murderers to hide their crimes behind a dishonest facade. To do away with the practice of forgiving people who kill in self-defense in order to make it impossible for some murderer to succeed in his crime, is like throwing the baby out with the bath water. It is true that the acceptance of killing in self-defense could be used by a murderer to hide his crime, but that is why we have standards of evidence and juries. Likewise, in the case of euthanasia, some might murder and call it euthanasia. We have to catch these people and punish them. To make all euthanasia illegal, however, assumes that we are not capable of differentiating the good from the bad. That assumption seems excessive.

To finish this argument it is important to note that the modern American discussion of physician assisted suicide is taking place in the format of a public debate. We know that we are in a dangerous place. Understanding the dangers that are present does not create an opportunity to slide down a slope. Rather, it raises our awareness, heightens our alertness, and generates the sort of conscientiousness that thwarts the psychological slippery slope.

There is one other type of slippery slope that might fare better, however, and that is the logical variety. The logical slippery slope says that the very same arguments that justify physician assisted suicide would also justify other, morally unacceptable, practices. According to this line of reasoning, if we allow a person with advanced metastatic cancer to select suicide because she does not want to experience the pain of a protracted illness, we must also allow the person with Alzheimer's to do the same. But the person with Alzheimer's is not terminally ill. Nevertheless, if avoidance of pain is an acceptable justification, it prevails in both cases and the slope is slippery.

Two responses are available here. The first is to deny the logical connection between the cases and argue that terminal illness is a morally necessary criteria for physician assisted suicide. If that is possible, then the slippery slope fails. If that is not possible, then the slippery slope prevails.

On the assumption that the slippery slope prevails, there is still one possible argument left. We can accept the slope but deny that it leads to absurd conclusions. In other words, we can thank the proponent of the argument for clarifying our judgment. "You are right", we might say. "I never realized that my view of physician assisted suicide entails allowances for people with irreversible but not terminal illness. Now that I see this, I am happy to broaden my view and accept the plausibility that physician assisted suicide is reasonable in the Alzheimer's case."

The beauty of this line of reasoning is that it knocks the wind out of the slippery slope sails. By admitting exactly what you are accused of, the accusation becomes powerless. Perhaps we were overly restrictive to begin with, and we ought morally to accept the broader implications of our view.

What happens, though, when the consequences outlined really are ethically embarrassing? What if we don't want to allow the killing of Alzheimer's patients? In that case, we thank the slippery slope once again for clarifying our view and showing us that a more restrictive moral position is in order.

In conclusion it seems that the use of slippery slope arguments no longer appears to be a rhetorical device for factional dispute. The slippery slope is a tool for clarifying the implications of our views. Either the slippery slope opens our eyes and forces us to accept as right some things that initially seemed untenable, or it shows us the unreasonableness of our initial, unreflective view. In either event we are better off, and the slippery slope becomes a method of philosophical discovery rather than a tool for winning arguments.