ISSA Proceedings 1998 – Slippery Slopes: The Reciprocal Of A Node On A Curve Or Surface

ISSAlogo1998The idea of slippery slopes is a commanding and attractive metaphor. Indeed, speaking in this way has become commonplace in contemporary work in biomedical ethics.[i] It would be interesting to know whether this metaphor has a load-bearing role in philosophical analysis; whether, that is, it is anything more than une façon de parler, a figure of speech.[ii] In work underway I pursue this question in three theoretical contexts:
1. analogical arguments,
2. sorites arguments, and
3. the analysis of taboos.
Unless I am mistaken, we shall hit paydirt in the third context, and this is the context I wish to explore in this paper.

Slippery slopes in relation to taboos
In one of its meanings, a taboo is a deep cultural protection of a value, underwritten by broad and largely tacit societal consensus. In my usage here, a taboo is always an ordered pair X in which P is a principle protecting a value – usually a prohibition – and X is an exclusion, an embedded practice which excludes P itself from free enquiry, from the rough-and-tumble of dialectical probing. Sometimes the X-factor also precludes the mention in polite society of the practice prohibited by P; but its more general implication is averting discussion of P’s merits, of whether it is a justified principle and if so by virtue of what. If, for example, P is the principle that prohibits cannibalism then X is the determination not to expose P to critical reflection or scrutiny. Indeed if X is the present-day taboo against Holocaust revisionism, the X-factor operates so tenaciously as to make of the mere raising of the revisionist possibility, no matter how tentatively, an immediate self-disqualification.[iii] In the absence of the X-factor, P cannot be a taboo. In societies such as ours there is a principle which strenuously disenjoins urinating in public, but it is no taboo. Except in the most delicate of circles, there is no corresponding bar against explanation and justification, or meeting arguments which might be marshaled against the prohibition (e.g., that there is no such prohibition for males in Japan). Taboos, then, are special cases of principles or points of view attended by dialectically weak – or even non-existent – track records. Of course, there are whole classes of dialectically impotent statements, whose lack of justificatory vigour is a reflection of the fact that they are seen as not needing defence or justification. They are “self-evident”, or “common knowledge”, or some such thing. With taboos, however, dialectical impotence is less a matter of judging that a defence is not needed than that it should not even be attempted. (I return to this point.)
Many taboos were once religious proscriptions. This helps in understanding both the X-factor and the dialectical impotence that attaches to taboos even after they have lost their religious sanctions. Though shorn of this expressly religious backing, we seem to retain them out of culturally transmitted habit. When they were religious laws, they required no justification by us; indeed to raise the question of whether something commanded by God might require our justification is to risk the sin of hubris. These features are retained as the X-factor and, relatedly, a pallid dialectical track record. Other taboos such as the one against the eating of pork may be seen as risk averse generalizations from genuinely factual data, a stong induction from an occassional upset tummy.[iv] Epistemically, the generalizations are hasty; prudentially they are safe. Risk averse behaviour is tailor-made for taboos. In fact, a good deal of risk averse behaviour involves the holding of generalizations that we don’t know how to justify, or which we subconsciously see as having no inductive justification. (Of course, it doesn’t follow that risk averse behaviour is likewise without strategic justification). Thus our disinclination to raise the question of how these generalizations are justified, and the consequent lightness of the dialectical track record.

Let me here enter a caveat. I do not assume that my conception of taboo concurs fully with contemporary anthropological usage. My first interest is in structures of X sort, and is much less in the lexical niceties. Indeed, perhaps it would be prudent to stipulate my “taboo” as a technical term.[v]
Taboos come in degrees, though not exactly on a scale of one to ten. At the high end we could expect to find the cannibalism taboo; slightly lower down, perhaps, the incest taboo; and – almost another thing entirely – the prohibition, in 1948 say, of  homosexuality. These differences reflect themselves mainly in our response to violation of a P, rather than that of an X. No one in my neighbourhood is a cannibal, but I daresay that the discovery of a cannibalistic cult next door would be met with utter outrage and outright condemnation.[vi] Incest differs on two counts. Comparatively speaking, there is a lot of it around, and when it is discovered it is prosecuted, and may be the object of substantial even though less sweeping public disapproval. The prohibition against homosexuality was much sinned against even in 1948; but except for errant celebrities, a homosexual’s defections were the object of local rather than wholly general public condemnation. For all the differences, these prohibitions retained their status as taboos by virtue of the X-factor, the factor which precludes any enquiry into the permissibility of P-hood of a sort which might eventuate in downgrading the prohibited practice from its standing as a public wrong. In certain cases, therefore, taboos are a kind of social hypocrisy. They lend, in any event, hefty encouragement to discretion. It is an interesting dynamic, in which getting caught is sometimes the greater wrong than what one was caught at.
In some respects, taboos resemble conventions. Conventions I take in David Lewis’ way; they are solutions of co-ordination problems.[vii] In a classic example, the conventions on driving – on the right in countries such as Canada and on the left in countries such as Japan – are regulators of traffic’s ebb and flow. In such cases, there is no prior fact of the matter as to which side of the road is the correct side to drive on in Canada, or in Japan. The only facts of the matter are the facts which our respective conventions constitute. If taboos resemble conventions closely enough, there is reason to think that, in some cases at least, they will imbibe this feature of them. If so, the existence of the X-factor can now be seen to be a highly-motivated constituent of such taboos. Taboos carry the cachet of high moral dudgeon and of confident certainty. Under their sway, people are easily disgusted and quick to dismiss the contrary view out of hand. If a taboo is a convention or sufficiently like a convention, there is no prior fact of the matter which the taboo reports or honours. The X-factor prohibits open enquiry. It does so for a reason, as we now see. Open inquiry might well disclose that the taboo records no prior fact, hence no fact which could be seen as sustaining it. This in turn affords an explanation of the dialectical impotence of taboos; for to scrutinize a taboo is to collapse it.[viii]

Taboos sometimes have something of the character of the first principles or absolute presuppositions of normal science. They resemble Kuhnian paradigms. If a paradigm cracks, nothing less then a chunk of normal science is in the balance, and a scientific revolution may well be in store. If a taboo cracks, events of like gravamen portend – the collapse of a large chunk of case law, or of public morality, and the prospect of an axiological revolution.
Taboos are the natural enemy of other principles we hold dear. One of these is our affection for free and open inquiry. Taboos embed principles P under the protection of dialectical exclusions X. The Ps of Xs have not had occasion to win their dialectical spurs. This makes them especially vulnerable to attack when it chances that they are attached. So, taboos sometimes crack. They wear out. They lapse. When this happens, violations of the X-factor are made in ways that are tolerated or even sponsored by decision-makers and shapers of public opinion – Walter Lipmann’s “dominant élites”. Thus a practice heretofore subject to a taboo might become the subject of a Government White Paper, a series of editorials in the Times, or even the “full hour” with Larry King. When the X-factor is violated by dominant élites, there is a good chance that this alone constitutes its retirement, and we have it straightaway that the P in question has lost its status as a taboo. It is now fair game for dialectical attack which its prior status as a taboo has given it scant fire-power now to resist. This is a point worth emphasizing. So I ask the reader a blunt question, “What precisely would you say in defence of the proposition that cannibalism is an abomination?”If I might answer my own question, I haven’t a clue.

The sexual revolution
Some taboos prohibit what people in any event have little interest in or stomach for, as we have seen. Others prohibit what lots and lots of people are keen to do and would do but for the prohibition.
Let us think of the former as pro forma and the latter as substantial taboos. Let me now suggest that the collapse of a substantial taboo constitutes a slippery slope. In its use here, slippery slopes aren’t arguments, not anyhow in any sense that a logician would want for his technical appropriations. Rather they are histories of dialectic, patterns of public and private acceptance and rejection, having, to be sure, arguments as constituent elements, as well the structural features that I shall now try to describe. It will facilitate the exposition if I take as an example a slope that has been slipped down pretty nearly as far as can be, a complex social event of the last fifty years. Before turning to the example, it is useful to stress an asymmetry between what people would have thought of it in 1948 and what people think of it now, a point to which I shall also recur. Let us now re-visit or, as the case may be, imagine the year 1948. The more or less settled consensus about sexual relations was that they were forbidden except under the following conditions: Marriage, and therefore, heterosexuality, adulthood and monogamy; as well as consent, privacy, and the “penile-vaginal modality” (if the linguistic barbarism can be forgiven).
I do not say that the consensus in question had the status of a taboo in 1948. Indeed it was a convention under attack. The attack was modest. It proposed a small relaxation of the conditions cited in (1). Marriage would be displaced by engagement, or going-steady or some such thing, hence by a simulacrum of it. Yet in the space of a dozen years, only the conditions of heterosexuality, adulthood, consent and privacy would remain, and the adulthood condition was in process of re-interpretation as biological maturity.
This, of course, was the beginning of the sexual revolution. Once the only-in-marriage condition lapsed, it became increasingly difficult to retain the conditions implied by it.[ix] Even as the sexual revolution was in full flower, two taboos remained, though they endured with differential tenacity. One was the prohibition against homosexuality, the other against paedophelia. Even so, the taboo against homosexuality was fraying. How could it not have done? If the marriage-condition had lapsed, and the penile-vaginal condition[x] too, there remained little to say for the heterosexuality which those constraints imply. The heterosexuality constraint was now on its own. Indeed, the conditions that were left in force bore all the weight of our disapproval of sexual licence: adulthood, consent, and privacy, supplemented perhaps by the desiderata of tenderness and respect.
The original prohibition was against all sexual relations save in marriage. When marriage ceased being a sacrament and was well on its way to what a “pre-nup” would provide – “a mere piece of paper” as the saying has it – what was there to say for its utter dominance as a constraint? Indeed, upon reflection, what was to be said for it at all as a constraint? With the marriage-condition gone, I say again that the other specifically anti-homosexuality conditions lost their most secure mooring.
Of course, the permissibility that came to attach to heterosexual relations outside of marriage was not transmitted to homosexuality by the relation of logical consequence. When the only-in-marriage condition was in effect, it did make homosexual relations impermissible on the received, and still widely held, view of marriage. But to infer permissibility of homosexual relations from the collapse of the only-in-marriage condition would be the ancient fallacy of denying the antecedent, a logical howler and a logical embarrassment. The linkage that we are trying to describe is not a logical but rather a dialectical one. To see how this is so, let us remark that the inference we have denounced could be redeemed with a replacement premiss, however implausible on its face, to the effect that the marriage-condition is the only prohibitor of homosexual practice.

The question now is whether there is any reason to suppose that the sexual revolution were actually disposed to accept this premiss, and if so, why? Actual dialectical experience suggests that they were in a classic situation ad ignorantiam, as we ourselves are today. Short of the only-in-marriage condition, we found ourselves without convincing or plausible cases to press against homosexuality. It is a situation in which continued resistance takes on a texture of arbitrariness and prejudice. It is a situation in which our failure to find a convincing case against homosexuality eventuates in a disposition to suppose that no such case exists. It is disposition, that is to say, to favour an argument ad ignorantiam[xi]:
1. We don’t know of a convincing case against homosexuality.
2. Therefore, there is no such case.
Ad ignorantiam arguments are sometimes fallacious, needless to say. But they commit no fallacy where interpretable either as an autoepistemic argument such as
A. If there were a convincing case against homosexuality we would know what it is (by now)
B. But we don’t
A. So there isn’t or as an abductive argument such as:
A. The best explanation of our not having a convincing case against homosexuality is that there is no case
A. We haven’t, in fact, a convincing case against homosexuality
A. So it is plausible to conjuncture that no such case exists.

The autoepistemic argument is valid by modus tollens; and while the abductive argument is invalid if construed deductively, this is not the intended construal, as the tentativeness of its conclusion makes clear. In each case the main weight of the argument is borne by the first premiss. It is one thing to know whether these premisses are actually true; it is another and easier thing to suppose that in our failure to find convincing case against homosexuality, we might come to believe that they are true. The key factor in this dynamic is dialectical fatigue. With the lapse of the marriage-only condition we find that we have nothing effective to say against homosexuality. This produces dialectical fatigue which, in turn, delivers the key premiss in the autoepistemic and abductive arguments here sketched. Thus while there is no direct logical link between the rescindment of the marriage condition and the non-existence of a persuasive case against homosexuality, the dialectical fatigue which ensued upon the retirement of that condition does indeed set up some logic, and some rather powerful logic at that.
The attack on the marriage-only condition was intended to promote the modest-seeming reform we have noted. Those pressing for this reform hadn’t – for the most part anyhow – the slightest idea or intent that homosexuality would be in the ambit of its escape. They pressed their arguments innocently. They were innocent of two things, one already noted, and another which I shall mention now. The first is that when a taboo loses the protection of its X-factor, the principle it previously protected lacks the dialectical means to defend itself. The second point is that once its X-protection is lost, a newly qualified P stands little chance of reacquiring the status of a taboo, hence the protection of the X-factor. This is certainly empirically borne out by what is known of axiological collapse on the hoof, i.e., in real-life. The likely explanation is that taboos are the result of cultural evolution, and that once the taboo against unmarried sex collapsed, the culture lacked the time to re-set the taboo a notch below, so to speak.
We see in this, well enough, the elements of slippery slope. Slope is the reduction in the number, and sometimes the weight, of the original clauses of a prohibition. Slipperiness is the lack of dialectical resources to minimize the elimination of them, indeed to cut off at any point. (And here we see the general pattern of sorites arguments). If what I have been suggesting in this section has any merit, we should ready ourselves for more slippage still in the arena of sexual mores. For reasons of time, however, I shall have to defer this issue to another occasion.

i. See, for example, Wesley J. Smith, Forced Exit: the Slippery Slope From Assisted Suicide to Legalized Murder, New York: Times Books 1997, and Peter Singer, Rethinking Life and Death: The Collapse of Our Traditional Ethics, New York: St. Martin’s Press 1994.
ii. Not to overlook Douglas Walton’s book, Slippery Slope Arguments, Oxford: Clarendon Press 1992.
iii. I thank Paul Viminitz for the example.
iv. Conversation with Kent Peacock suggested this possibility to me.
v. A suggestion put to me by Barry Allen.
vi. Against this it might be doubted that there is any taboo against cannibalism. In countries like Canada, there is no economic or sacerdotal motive for people even to consider the cannibalistic option. So they don’t; and that they don’t is reflected in the uniformity of their behaviour. If a taboo always involves a prohibition, we may wonder whether it is possible to prohibit what no one seems to have the slightest interest in doing. This suggests that Canadian avoidance of cannibalism is not the result of a taboo. On the other hand, no one in Canada wears Elizabethan garb. One could say that non-Elizabethan dress is the settled Canadian practice. There is nothing to say for there being a prohibition against Elizabethan costuming, and nothing for there being a taboo against it. Even so, the two cases harbour a significant difference. If people started dressing in this fashion, others might approve or disapprove; but there would be no prohibition. If people started setting up Hell’s Angels’ Cannibal clubs, there would , as I say, be outrage and universal condemnation. The taboo which was only counterfactually in play would now be realized. (I am indebted to Bryson Brown on this point.) In contrast with the situation in Canada, as Inga Dolinina informs me, during the siege of Leningrad in the Great Patriotic War, cannibalism was rife, and it continued after the siege was lifted, more as a matter of choice than of dire necessity, and had to be stopped by vigorous intervention of state authorities.
vii. David K. Lewis, Convention: A Philosophical Study, Cambridge, MA: Harvard University Press 1969.
viii. In a nice turn of phrase suggested by Michael Stingl in conversation.
ix. Until the pill, timely marriage was also a fail-safe strategy against bastardy, itself then the subject of a taboo. It is difficult to overestimate the influence of contraceptive technologies in the heterosexual sector of the sexual revolution. The story of this influence is well-understood and need not be developed here.
x. Itself a casuality of the displacement of the only-in-marriage condition, as it relates to procreative intent.
xi. John Locke is the originator of the name “ad ignorantiam”. In its use here it means “to ignorance”. In the concluding paragraphs of chapter 17 of his Essay Concerning Human Understanding (1690) Locke describes the argumentum ad ignorantiam as follows: “Another way that men ordinarily use to drive others and force them to submit their judgements and receive the opinion in a debate is to require the adversary to admit what they allege as a proof, or to assign a better”. Thus, if you are ignorant of such a proof, you must yield; and my argument against you is directed to that ignorance. Locke did not think that ad ignorantiam arguments were fallacious as such, but this has not stopped writers of the present day taking the opposite view. On a common contemporary conception of it, an ad ignorantiam is an argument whose elementary form is It is not known that not-P Therefore, P. Here, too, “ad ignorantiam” speaks for itself. I indicate in the body of this chapter, just below, why certain instances of this form are not fallacious.