On Slippery Slopes

Is there a straight line leading from ‘the shot heard round the world’ to endemic divorce, gangsta rap, and the North American Man-Boy Love Association?
McClay, 1998:20
Someone proposes to remove all penalties from the production, sale, possession and use of marijuana, but to forbid its producers to advertise (except by word of mouth). If such a proposal could be made to work, it might provide an attractive way of resolving disputes about the legal standing of a wide range of controversial practices, including the use of ‘soft’ drugs of all sorts. Even pro-life people would find legal abortion easier to accept if clinics were not advertised in the Yellow Pages.
But there is reason to doubt that such a compromise would be stable. First, the Supreme Court has struck down restrictions on commercial speech. (44 Liquormart Inc. v. Rhode Island, 517 US 489 (1996)). Second, even if the Court could be prepared to rescind or sharply limit its commercial speech doctrine a profitable and therefore politically powerful marijuana industry would press in both the legislature and among the electorate for the removal of its disadvantages. They would charge unfairness, pointing out that neither the liquor nor the tobacco industry labors under a similar disability.
THE ARGUMENT IN GENERAL
We are here dealing with the slippery slope argument (SSA), as often scorned by philosophers, though often with such unhelpful qualifying phrases as “if the likelihood of such trouble is exaggerated. (Dowden 1993:A8-9, Rafalko, 1990:446) as it has been invoked by jurists and political advocates. Many critics have dismissed the SSA as the last resort of the traditionalists bereft of better arguments (for a compendium, see Lode .1998: 1473-74).
Textbook discussions of this alleged fallacy are systematically inadequate, in a way that reflects the authors’ sympathy for proposals against which SSA’s have been deployed. Thus the premier American logic textbook (Copi, Cohen, and McMahon, 2011:131-32) cites a “keen critic” for the following response to the SSA against physician assisted suicide.
Physicians often prescribe drugs which, in doses greater than prescribed, would kill the patient. No one fears that the actual dose prescribed will lead to their use in lethal doses. No one objects to such prescriptions for fear of a “slippery slope” (van den Haag 1995).
At the same time it endorses the following SSA against punishing hate crimes more severely than ordinary crimes.
There should not be a separate category for hate crimes. A murder is a murder; a beating is a beating. We should prosecute people for the crimes they commit, not why they commit them. If we start to categorize crimes by their motivation, we start down a very slippery slope. (Simpser, 2002)
But the first of these quotations ignores the line, salient on any view of which I am aware, between acts that intentionally take human life and acts that do not. And the second, fails to specify bad effects arising from motive-defined criminal laws comparable to a doctor’s deliberately killing his unprofitable patients or pressuring them to kill themselves. (Like most bad arguments it can be improved.)
I here argue that SSA’s, though not deductively coercive, sometimes give us strong reasons to reject an initially attractive proposal. Such a proposal need not be acceptable in itself, (as Lode, 1999: 1481, points out against Schauer, 1985: 369) but unless someone finds it appealing, there is no need for an SSA. If an otherwise seemingly acceptable A (in my initial example, legal marijuana without advertisement) threatens to lead to an unacceptable B (dealers aggressively marketing marijuana to the population including children), this is a reason, though not always a decisive reason, for rejecting A. That the argument is non-deductive, and sometimes leads us astray, is no argument against my thesis. The same could be said of induction.
Slippery slopes happen, even if sometimes we welcome their results. If a white Southerner argued in 1860 that abolishing slavery would lead to legal intermarriage and an African-American President, his historical prophesies would have been correct. We might not think that the bottom of the slope was a bad place , but that — my hypothetical pro-slavery writer would say – is exactly what we should expect. And those who promoted this development appealed to benign slippery slopes: Frederick Douglass, urging his fellow African Americans to enlist in the Union Army maintained, correctly, that the limited emancipation proclaimed by President Lincoln made general emancipation inevitable (Douglas .2011: 514.)
Moreover, the outcome of some slippery slopes is bad by any standard. The erosion of constitutional government in Weimar Germany led first, to more and more extensive use of emergency decrees to circumvent legislative deadlock, through the overthrow of the Prussian state government, through the summary killing of Hitler’s rivals in the Nazi Party in Night of the Long Knives, through the euthanasia campaign, and lastly to the Holocaust. The doctrines of the jurist Carl Schmitt facilitated this development (Kennedy 2004).
We may also observe the slippery slope at work in areas of contemporary controversy. The Supreme Court of Vermont, by way of imposing same-sex (quasi-) marriage on the state, turned the sour conservative maxim, Give some people an inch and they will take a mile, in to an imperative of constitutional jurisprudence. The court reasoned,
The State asserts that [the goal of promoting child rearing in a setting that provides both male and female role models] could support a legislative decision to exclude same-sex partners from the statutory benefits and protections of marriage. … The argument, however, contains a … fundamental flaw, and that is that is the Legislature’s endorsement of a policy diametrically at odds with the State’s claim. In 1996, [the Legislature removed] all prior legal barriers to the adoption of children by same-sex couples. At the same time, the Legislature provided additional legal protections in the form of court-ordered child support in the event that the same-sex parents dissolved their partnership. In the light of these express policy choices, the State’s arguments that Vermont public policies favors opposite-sex over same parents or disfavors the use of artificial reproductive technologies are patently without substance. (Baker v. State, 744 A 2d 864, 884-885 [Vt., 1999])
Whether the bottom of this particular slippery slope is a bad place t is controversial. But many of my readers, whatever their views on marriage, will be troubled by the story of euthanasia in the Netherlands.
Dutch courts began by declining to punish doctors who assisted the suicides of the terminally ill. They then extended this principle to cover patients who were victims of “unbearable suffering,” without any requirement that the patients be terminally ill. They then extended to the principle to cover who was in seemingly irremediable mental pain, caused by chronic depression, alcohol abuse, on the theory that the suffering of the mentally ill is “subjectively experienced as unbearable” by them, comparable to how the physically ill experience physical suffering. Dutch courts then extended this principle to cover a fifty-year-old woman who was in mental pain partly caused by the death of her two sons, again the theory that her suffering was unbearable. (Volokh, 2003: 1058-1059)
In any event, the central question raised by SSAs is that of evaluation. If the status quo before the proposed change is bad enough, or the condition at the bottom of the slope is relatively acceptable, then the slippery slope argument will fail. To recur to my original example, someone who finds the present “War on Drugs” intolerable, or views with aplomb the aggressive marketing of recreational drugs to children, will not be troubled by the difficulty of maintaining a ban on marijuana advertising in practice.
The question of historical causation is complicated. Ideas have consequences, but they are not the only thing that has consequences. Nor are the consequences of ideas in practice always what one might expect them to be in the abstract. In practice, this means that when an acceptable change A is followed by an unacceptable result B, it is often uncertain that that it was A, rather than some other development within the society in question that is to blame for B. Which battles to fight, and which are the most important, is an inescapably prudential question. But the counsel to avoid bad results by opposing bad beginnings remains sound, however complicated its application in practice.
Even when we speak of actions rather than justifications, the SSA concerns, not bare behavior (if there is such a thing), but behavior understood and legitimated in certain terms – as the exercise of a constitutional right for example. Hence some legal or legal-like formulary is always in the background.
Some facts about language are therefore crucial. With one narrow class of exceptions, all language is open to interpretation. The exception is the rules of a game such as chess, in which the number of possible positions is both finite and precise, however enormous. Aside from such cases, legal formularies fall upon a continuum with respect to the extent to which they invite dispute about their application. That each State of the American Union is entitled to two Senators raises serious interpretive issues only under conditions of plague or civil war, where the issue is whether the relevant entity is entitled to act as a State. On the other end of the continuum, the notorious ‘mystery’ doctrine (“At the heart of liberty is the right to define one’s own concept of existence, of the meaning of the universe, and of the mystery of human life.”) is as indeterminate as a formulary can be without losing all content. For there is no conduct – whether suicide bombing or pursuing wealth in ways dangerous to the nation’s economic stability – that could not be defended as a way of responding to the mystery of human existence. .
As Eric Lode has pointed out, “People frequently remain steady in their application of vague terms. (Lode, 1999: 1509) But this is true only when the background understandings that govern their use are stable. Our legal system, however, has its home in a world where many different groups strive to push it in a direction they desire. Vague doctrines cover up clashing agendas, in way that can smooth a slippery slope. As Mario J. Rizzo and Douglas Glen Whitman point out,
The existence of multiple theories can lead to the adoption of political, legal, and ethical doctrines that are deliberately vague. For instance, politicians will sometimes pass intentionally vague legislation in order to avoid having to make tough decisions, thereby passing the buck to bureaucratic agencies. Balancing “rules” in the common law, which direct judges to weigh a variety of factors when deciding cases, are arguably a means of finessing the differences among judges’ theories. … Even if vague terms are not deliberately adopted to cover up differences of opinion, they may nonetheless have the same effect. Rizzo and Whitman, 2003:575-76).
In many cases the demand for legal or policy consistency generates slippery slopes. If two elements of the law are in tension with another, then the inconsistency can be resolved in more than one way. But each of them will be regarded, by some parties to the dispute as involving a slippery slope in an undesirable direction (Rizzo and Whitman, 2003: 565-66 and n.74, discussing People v. Kurr, 654 N.W.2d 65 [Mich. Ct. App. 2002]). For these reasons, SSAs in real-life practical discourse are not “sorites SSAs,” which exploit the inevitable open texture of language to oppose the extension of a term even part of the way into a contested area (despite Marmor, 2012:10). For example, someone might argue against severe taxation of the top one percent that there is no clear line between rich and poor, and that everyone would then be at risk of expropriation. Or we should not exempt low income people from the income tax, lest we end up without any revenue. Such SSAs would bring practical reasoning to an end. In real SSAs, there is always some principle or social force pushing us down the slope; the issue is its intellectual or political power.
Logic is one thing, and social psychology another. As Lode puts it, “Effective distinctions may fail to be reasonable. … Similarly ,reasonable distinctions might not be effective” (Lode, 1999: 1479). The reason for this phenomenon is, as Rizzo and Whitman observe,
The process by which arguments are accepted and decisions made is a social one that derives fromthe decisions of many individuals. …The person who makes an SSA does not necessarily claim that the listener himself will be the perpetrator of the future bad decision. Rather, he draws attention to the structure of the discussion that will shape the decisions of many decisionmakers involved in a social process. (Rizzo and Whitman, 2003:571).
Thus arguments and principles employed by people with one agenda may be captured by others whose agenda is very different and possibly even abhorrent to those who make the original argument.
There are three different kinds of argument that go by the name slippery slope. One is an argument by analogy, the second looks to the nature of the justifications offered, and the third relies, not on intellectual considerations, but on the dynamics of social and political life.
THE ANALOGICAL SLIPPERY SLOPE
Arguments by analogy pervade discussion of practical issues, both in the law and in more informal contexts. Here are two influential examples:
(A)
(1) Legal and social distinctions based on race are obnoxious.
(2) Distinctions based on sexual orientation are, in relevant respects, similar to distinctions based on race.
(3) Therefore, legal and social distinctions based on sexual orientation are obnoxious.
(B)
(1) Discrimination against African Americans, Hispanics, Asians, and Native Americans is unacceptable.
(2) Discrimination against white people is, in relevant respects, similar to discrimination against African Americans, Hispanics, Asians, and Native Americans.
(3) Therefore, discrimination against white people, say in programs of preferential affirmative action, is unacceptable.
Neither (A) nor (B) ends the argument. Those who reject their conclusions argue that the cases are relevantly different; an argument by analogy can always be answered with a distinction. But neither are they are irrelevant: they present a case their opponents are obliged to answer.
An analogical SSA involves a repeated use of analogy. Thus for example:
(C)
(1) Infanticide is immoral and ought to be illegal.
(2) Late abortion is in relevant respects similar to infanticide.
(3) Early abortion is in relevant respects similar to late abortion.
(4) Therefore, early abortion is immoral and ought to be illegal.
Writers hostile to SSA’s take (C) as their paradigm of the alleged fallacy. But there is nothing inherently wrong with it: it differs from (A) and (B) only in that it reiterates the analogy. And like them, while not decisive, it presents an argument its opponents are obliged to answer.
What (C) calls for is what is somewhat brutally called a “cutoff point” – an intellectually and politically defensible line between a human being or person and pre-human organic matter. Its proponents also need such a cut-off point, in order to rebut the suggestion that they are committed to the absurd result that any abstention from reproduction is murderous. But, since 1827, we have known of at least one clearly defensible cut-off point: the moment of conception.
But why not draw an arbitrary line, as we do when we designate a speed limit? The answer lies in the gravity of the issue at stake. The “mistakes are fatal” argument against capital punishment is very popular, though it has its problems (see Devine, 2000). But a parallel argument against punishing minor traffic offenses would be grotesque. We can be unconcerned about arbitrariness in the voting age, since a sixteen-year old need only wait two years for full citizenship. And a similar point holds for jury size, since there is no reason to believe that six-person juries are especially likely to perpetrate miscarriages of justice. But if we were to establish a maximum voting age, whether that age were seventy-five or eighty would be a more sensitive issue. The issue would be more sensitive still, if we accepted the proposal that people beyond a certain age were to be killed or denied life-saving medical care. Likewise, the possibility that we define the line between persons and non-persons in such a way as to wrongly exclude some entities from personhood ought to give us serious concern.
I draw two conclusions from this argument. One is that Bernard Williams is wrong to distinguish “horrible result” from “arbitrary result” SSAs (Williams, 1985). Slippery slopes trouble us only because their results can be horrible (though some possible results, such as endless litigation, are horrible only relatively speaking).
Second, Williams is correct to see that slippery slopes are inherent in some of our language, for example the word person as commonly used by bioethicists. In his own words,
There are some absolute terms, the absolute character of which is only a verbal matter, a substantival wrap for a content which is basically comparative. … A very important and misleading example is ‘person’, as that term is sometimes used by philosophers in ethical connections [his example is Tooley, 1989] It is formally true that no one can be more of a person than anyone else, but almost all the characteristics associated by these philosophers with being a person … come in degrees. … This concept, despite its absolute appearance, will provide no firm basis for rules about killing and similar matters, and those who place faith in it are deceiving themselves. (Williams, 1985:136-37)
This slope has in fact been exploited by some writers in bioethics (for example English, 1975).
If we find this result unacceptable, we have three choices. We can adopt a “precising definition’ of person, designed to remove or reduce its vagueness or open texture (see, for example, Fogelin, 1987: 83-84.) But these definitions commonly have considerable open texture as well.
A second approach is to embrace the open texture of the relevant concepts, and adopt, for example, a ‘gradualist’ approach to the fetus question. The problem lies in establishing an intellectually and politically defensible correlation between stages of development and ‘indications.’ We lack the necessary conceptual equipment for this task, in part because the moral metaphysics of the West treats personhood as an on-off category, and affirms that all persons (however much inequality we may tolerate at the practical level) as inherently equal. In traditional Hindu thought, by contrast, killing a Brahmin was the worst of offenses, though this did not mean that killing members of other castes was acceptable. Abortion in particular was a paradigm of evil behavior. To the (limited) extent that I understand this way of thought, the abortion of a male, Brahmin fetus is about the worst thing a human being can do (see Mahābhārata, 1.149.7, 1.56.17, .van Buitenen, 1988:309,129)
A third approach is to brave the charge of ‘speciesism’ and formulate the relevant rules in terms of membership in the human species. Member of extraterrestrial species, or even chimpanzees and dolphins, might also end up getting recognized as, as was said in the sixteenth century of American Indians/Native Americans, as “true men” (Pope Paul III, Sublimis Deus (1537). Cited in, Thomas, 1977:125). But such recognition would not be automatic, and would require both deliberation and experience.

THE ARGUMENTATIVE SLIPPERY SLOPE
The analogical slippery slope focuses on the objective characteristics of the pertinent actions, to the limited extent that these can be distinguished from the agent’s motives, intentions, and justifications. The argumentative slippery slope links forms of behavior that may look very different, but are linked by the justifications offered in their behalf. The form of the argument is as follows:
(1) All the arguments for A are also arguments for B.
(2) Therefore, those who accept A also should accept B.
Where such an argument is valid, refusing to accept it is to commit the ‘taxicab fallacy’ – of behaving like a lawyer who is content to win the case and hand and feels himself entitled to neglect the possible wider consequences of a favorable ruling.
Here are two examples:
(D)
(1) All the arguments for recognizing same-sex marriage are also arguments for recognizing polygamy.
(2) Therefore, any jurisdiction that, as a matter of principle, recognizes same-sex marriage should also recognize polygamy. (I exclude such considerations that gay men and lesbians often have more political power than fundamentalist Mormons or immigrants from polygamous societies.)
(E)
(1) All the arguments for a woman’s right to choose abortion are also arguments for a man’s right to accept the obligations of paternity (“Roe v. Wade for MenTM”) (concerning which see National Center for Men, n.d).
(2) Therefore those who accept Roe v. Wade for women ought also to accept it for men.
These arguments both seem good, at least in the absence of persuasive considerations to the contrary. In defense of (E), it is true that those people who oppose Roe v. Wade for women demand a greater sacrifice of people who have brought about a pregnancy than do those who oppose Roe v. Wade for men. But the proponents of Roe v. Wade for women also demand more for women than their counterparts do for men– not only to have no part in the child’s upbringing, but also to do something that prevents the child being brought up at all. I do not, however, expect the conclusions of (D) and (E) to be followed in practice.
THE PRUDENTIAL SLIPPERY SLOPE
Prudential SSAs are of the following form:
(1) Policy P will (or may) lead to result R.
(2) Result R is bad.
(3) Therefore, we should not adopt policy P.
Two prudential SSAs, each of which can be taken as a sample of a far larger family are
(F)
(1) Voluntary euthanasia will (or may) lead to non-voluntary and even compulsory euthanasia.
(2) Non-voluntary and especially compulsory euthanasia are bad.
(3) Therefore, we should not accept even voluntary euthanasia.
(The examples in Lamb, 1998, are all biomedical arguments broadly along these lines.)
(G)
(1) Holding aliens suspected of terrorism indefinitely without trial will lead to the internment of loyal American citizens (as happened to the Japanese Americans during World War II).
(2) The internment of loyal American citizens is bad.
(3) Therefore we should not hold aliens suspected of terrorism indefinitely without trial.
The same sort of argument applies to the assassination of alleged terrorist leaders.
Both (F) and (G) are consequentialist arguments, though they are both used – especially (F) – by writers whose approach to ethics is non-consequentialist. Consequentialist arguments cannot be avoided in ethics, despite Grisez, 1978, though to rely on consequences alone would produce a morality that we should reject on consequentialist grounds. Both also turn on the consequences of policies: not individual acts, but acts carried out under public authority by the light of day. The Nazi euthanasia campaign was somewhat clandestine, and arguably contributed to the, also somewhat clandestine, Holocaust. But if clandestine operations have untoward implications, we are entitled to expect that public policy announced by the White House, the Congress, or the Supreme Court will have such implications as well (and even more so)..
Whether a prudential slope is slippery depends on a host of socio-psychological mechanisms (see Volokh, 2003).. I here hit the high points only. The status quo in all societies outside the gates of Eden is the result of a compromise among a number of groups each having both their own distinctive material interests and their own distinctive understandings of the good society and the way to it. Some such groups are acutely unhappy with the status quo, and have a program for change. Sometimes accommodation or even alliance is possible but sometimes these programs clash deeply. The saying of Mao Tse-tung (n.d) “We shall support whatever the enemy opposes and oppose whatever the enemy supports,” has adherents these days all over the political spectrum.
Many members of disaffected groups would like to change things all at once, and some of them have moral objections to incrementalism (see Harte, 2005). But political effectiveness requires a willingness to proceed ‘step by step,’ if only to plant premises in the public mind that make possible more radical policies in the future (see Arkes, 2004: 247).And this means trying to push the larger society down a slippery slope.
As a result, a range of possibly attractive moderate positions become harder to defend. These range from moments of silence at the beginning of the school day, through “don’t ask, don’t tell” policies concerning homosexuality, to states’ rights approaches to the abortion issue. Some such proposals might be the best that can be done in an imperfect world. But we are constantly made conscious of the possibility that advocates of a moment of silence might, to put their opponents’ suspicions as charitably as possible, have a program for using state power to pressure children to pray.
Three further observations will conclude the discussion. First, an SSA cannot stand alone. If I have no inclination to believe that playing cards without gambling is morally offensive, I will not be moved by the suggestion that it leads to gambling addiction. Second, slippery slopes do not operate solo, but against a background perception that society is changing for the worse at least in some respects, and that moving with the times in these contexts means accepting deeper and deeper depravity. But, third, the fact that slippery slopes appear everywhere, and if always accepted would lead to paralysis means that such arguments must be used with prudence, though not that they are fallacious as such.
At every stage of the evaluation of an SSA a prudential judgment is required, both of the importance of the interests at stake of the power of the forces pushing us down the slope. Philosophers impatient with the messiness of the social world should renounce their ambition to be philosopher-kings (or queens).
The greatest source of belief in slippery slopes is to have observed a number of them. And the history of the institution of marriage and related issues contains many examples — so much so that one central purpose of the institution, securing the continued existence of communities across generations, is now under threat. The effect of SSA’s is to put pressure on those who advocate moderate reform, to show that their proposed changes will not have the deleterious global effects their opponents fear. Thoroughgoing radicals can ignore such arguments since they welcome such global effects. In that sense the SSA is a conservative argument.
.It is commonly said that people get more conservative as they get older. But a believer in the SSA, and in this sense a conservative, can consistently deplore the absence in our world of a genuinely participatory and democratic society within which the welfare of individual citizens is raised above theories and prejudices about alleged racial and ethnic superiority, and where individual interests have priority over economic dogmas and theories of social utility (Lamb, 1998:20). The sort of conservatism that comes with age is that of an investment strategy: a greater awareness of the possibly disastrous consequences of superficially attractive proposals.
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