Ethical slippery slope arguments deserve serious but not facile engagements. Below is a consideration of why some such arguments are oversimplified.
There is a taxonomy of slippery slope arguments [SSAs]. It distinguishes causal from logical arguments and further separates arguments per their results, arbitrary & horrible.
Causal arguments are concerned with domino-like effects. Logical arguments explore the in/consistency of rules, whether grounded in casuist, principlist or even consensual ethical decision-making approaches.
An arbitrary result is deemed objectionable by the mere fact that an argument has employed some type of slope. A horrible result refers to an argument which would permit morally repugnant outcomes.
Ethical slippery slope arguments are often of the logical-horrible variety.
Others have well-treated the logical in/consistencies & un/soundness that can afflict/bolster all manner of ethical SSAs. I will discuss, below, why we shouldn’t overstate the influence that formal argumentation has on societal maxims, rules & norms, why, for example, various case-holdings won’t inexorably unravel the moral fabric of society or, switching metaphors, send a rapid succession of taboo-boulders rolling down the ethical slopes of a culture’s moral highlands. I will also discuss whether the introduction of some degree of arbitrariness should a priori deligitimize an ethical decision-making approach.
The degree of consensus regarding humanity’s most general precepts remains largely sufficient to norm a modicum of public peace, public order, public justice & public morality, extending, for example, even to international declarations regarding human rights and to international law & treaties.
The more specific & concrete application of such precepts become much more problematical for thornier issues, e.g. bioethical realities regarding gender, sex & life issues.
A society’s laws & rules reflect a shared public reason & shared evaluative dispositions. It’s this overlapping consensus of mid-level principles & these mutual intuitions of common sensibilities that, together, constitute a relatively stable, wide, reflective equilibrium of moral reasoning.
Over against any Ethical Chicken Little hysteria, then, an ethical pluralism, grounded in a fallibilist epistemology & probabilist deontology, notwithstanding some unavoidable degree of inconsistency, need not explode into an ethical incoherence or moral relativism, much less trivialism.
Pluralistic societies can have different cohorts of naïve realists, each which may subscribe to its own particular, foundational moral theory with its distinct metaphysical commitments. Such cohorts will tend to imagine that a pluralistic society’s moral slopes are far more slippery than they actually are because they fail to recognize the limited relevance of their own theories & commitments to a given society’s maxims, rules & norms. They also tend to ignore the resilience & relative stability of the above-referenced reflective equilibrium, grounded as it is – not just in formal logic, but – in deeply felt evaluative dispositions, common sensibilities & ethical intuitions, which certainly can reflect an inchoate grasp of the natural law, secured by connatural inclinations. This remains the case even when such a grasp of the natural law remains rather difficult to articulate by formal argument (and not just difficult for the vox populi but also for the ethical literati).
Such a stable reflective equilibrium will generally stand in the way of any cascading of consensually, morally repugnant outcomes, when otherwise specific incremental changes are effected in societal rules & norms.
This is to recognize that Ethical Chicken Littles will too often make much ado about their own arguments, which are not more universally compelling, sometimes, because their logic is simply flawed, if not due to validity, then, by unsoundness; sometimes, because certain maxims, rules & norms have established their coherence & resiliency less so by formal argumentation, more so by innate connatural inclinations & subconscious social formations.
As with other apparent inconsistencies, dilemmas, aporiae or paradoxes, human common sense & sensibilities can often evade ethical conundra, practically, via reductio ad absurdum, while patiently abiding either their dissolutions via paradigm shifts or resolutions via dialectics.
We may not be able to formally articulate why a putative outcome would be impossible, improbable or absurd using a robustly truth-conducive triadic inference, but we can, most certainly, very often employ a veritable multitude of weakly truth-indicative abductions, logically, as well as evaluative dispositions & ethical intuitions, axio-logically, which, when bundled together into a preponderance, evidentially, can sufficiently justify a solidly probable moral proposition.
Over against any notion that slopes afflicted by degrees of arbitrariness must simply be avoided, we must recognize that we are ALREADY on such slopes, ubiquitously so. Such a notion could not survive the parody of purging all moral discourse of references to reality’s manifold & multiform dis/continua.
Thus, even among those who subscribe to a particular foundational moral theory as well as its deeper metaphysical commitments, the more critical (less naïve) realist cohorts will not overestimate the slipperiness of various moral slopes, for they recognize:
that our appropriations of moral realities ALREADY often involve approximations;
that our fallible grasps of moral realities ALREADY require the use of concepts that are not wholly essentialist but variously clustered, vague or fuzzy;
that human symbols, icons & indexes are ALREADY seldom going to be wholly nonarbitrary;
that the human mind ALREADY must often transcend rational formalities with common sense and informal & paraconsistent logics (see note below) in order to avoid absurdity & trivialism.
To the extent that epistemology models ontology, this variety of ethical approximations (conceptual, semiotic & logical) implicates various ontological dis/continuities, regarding – not only the spatio-temporal, materio-energetic continua of physical entities (e.g. age-related, developmental, genetic, non/strict identities), but – the causalities of physical events, including various teloi (e.g. teleopotent, teleomatic, teleonomic & teleologic).
For example, whatever one’s paradigm regarding non/strict identities, even an essentialist account might best resort to a conception of deep & dynamic formal fields.
The above taxonomy of SSAs & categories of axiological epistemology can still be rather insufficient, relying as they do on an implicit canon of common sense that can’t always be taken for granted. This is especially true, again, as we move from general precepts to their more specific, concrete applications. See, for example: An anthropological exploration of contemporary bioethics: the varieties of common sense. Turner L. , J Med Ethics. 1998 Apr;24(2):127-33.
N.B. From: http://www.iep.utm.edu/para-log/
If the mind is able to reason around contradiction without absurdity, then paraconsistent machines may be better able to model the mind.
Defending consistency, or denying the absurdity of trivialism, is ultimately not the job of logic alone. Affirming coherence and denying absurdity is an act, a job for human beings.
Put another way, a paraconsistent logician can say that a theory is inconsistent without meaning that the theory is incoherent, or absurd. The former is a structural feature of the theory, worth repair or further study; the latter means the theory has gone disastrously wrong. Paraconsistency gives us a principled way to resist equating contradiction with absurdity.