In this overview article, we first explain what we take informal logic to be, discussing misconceptions and distinguishing our conception of it from competing ones; second, we briefly catalogue recent informal logic research, under 14 headings; third, we suggest four broad areas of problems and questions for future research; fourth, we describe current scholarly resources for informal logic; fifth, we discuss three implications of informal logic for philosophy in particular, and take note ofpractical consequences of a more general sort.

Historically, the fallacies have been neglected as objects of systematic study. Yet, since Hamblin's famous criticism of the state of fallacy theory, a substantial literature has been produced. A large portion of this literature is the work of Douglas Walton and John Woods. This paper will deal directly with the criticism of that work which has been advanced by van Eemeren and Grootendorst, particularly the complaints found in their writings of 1992, concerning the disunification of the fallacies and the exemplaristic (...) approach of Woods and Walton's theories. It proposes a unification of the theories of Woods and Walton with that of van Eemeren and Grootendorst, and suggests that such a unification could be advantageous to both theories, and highly interesting for fallacy theory in general. (shrink)

Slippery slope arguments (SSAs) have often been viewed as inherently weak arguments, to be classified together with traditional fallacies of reasoning and argumentation such as circular arguments and arguments from ignorance. Over the last two decades several philosophers have taken a kinder view, often providing historical examples of the kind of gradual change on which slippery slope arguments rely. Against this background, Enoch (2001, Oxford Journal of Legal Studies 21(4), 629–647) presented a novel argument against SSA use that itself invokes (...) a slippery slope. Specifically, he argued that the very reasons that can make SSAs strong arguments mean that we should be poor at abiding by the distinction between good and bad SSAs, making SSAs inherently undesirable. We argue that Enoch’s meta-level SSA fails on both conceptual and empirical grounds. (shrink)

Agonist theorists have argued against deliberative democrats that democratic institutions should not seek to establish a rational consensus, but rather allow political disagreements to be expressed in an adversarial form. But democratic agonism is not antagonism: some restriction of the plurality of admissible expressions is not incompatible with a legitimate public sphere. However, is it generally possible to grant this distinction between antagonism and agonism without accepting normative standards in public discourse that saliently resemble those advocated by (some) deliberative democrats? (...) In this paper we provide an analysis of one important aspect of political communication, the use of slippery slope arguments, and show that the fact of pluralism weakens the agonists’ case for contestation as a sufficient ingredient for appropriately democratic public discourse. We illustrate that contention by identifying two specific kinds of what we call pluralism slippery slopes, i.e. mechanisms whereby pluralism reinforces the efficacy of slippery slope arguments. (shrink)

Both the traditional Aristotelian and modern symbolic approaches to logic have seen logic in terms of discrete symbol processing. Yet there are several kinds of argument whose validity depends on some topological notion of continuous variation, which is not well captured by discrete symbols. Examples include extrapolation and slippery slope arguments, sorites, fuzzy logic, and those involving closeness of possible worlds. It is argued that the natural first attempts to analyze these notions and explain their relation to reasoning fail, so (...) that ignorance of their nature is profound. (shrink)

In this paper, we use concepts, structure and tools from argumentation theory to show how conversational implicatures are triggered by conflicts of presumptions. Presumptive implicatures are shown to be based on defeasible forms of inference used in conditions of lack of knowledge, including analogical reasoning, inference to the best explanation, practical reasoning, appeal to pity, and argument from cause. Such inferences are modelled as communicative strategies to knowledge gaps that shift the burden of providing the missing contrary evidence to the (...) other party in a dialogue. Through a series of illustrative examples, we show how such principles of inference are based on common knowledge about the ordinary course of events shared by participants in a structured dialogue setting in which they take turns putting forward and responding to speech acts. (shrink)

Článek se věnuje argumentu kluzkého svahu a otázce, jak jej identifikovat a hodnotit. Argument kluzkého svahu je využíván v rámci praktického uvažování a v dialogu, svou strukturou odpovídá negativnímu argumentu z důsledku, má v zásadě defeasibilní povahu a je často účinný při snaze přenést důkazní břemeno na stranu oponenta. Hodnocení argumentu kluzkého svahu je založeno na kontextu dialogu spíše než na hodnocení jeho deduktivní či induktivní správnosti.V příspěvku jsou představeny čtyři typy argumentu. Zaprvé argument kluzkého svahu typu sorites, jehož označení (...) odkazuje k paradoxu sorites neboli paradoxu hromady. Argument kluzkého svahu typu sorites je ve své podstatě kombinací argumentu ad absurdum a sofismatu polyzeteseos. Zadruhé kauzální argument kluzkého svahu, který se zakládá na předpovědi série událostí. Tento typ argumentu je často označován jako teorie domina či dominový efekt. Nicméně, ať už jej pojmenujeme jakkoli, zásadní pro jeho identifikaci, analýzu a hodnocení je fakt, že se jedná o předpověď budoucího stavu věcí. Předpověď více či méně pravděpodobnou, zakládající se na slabých či silných předpokladech. Zatřetí precedentální argument kluzkého svahu, který se objevuje v diskuzích o možnosti změny současného pravidla či platné normy. Argumenty založené na precedentu obecně souvisí s usuzováním na základě konkrétního případu. Precedentální argument kluzkého svahu využívá podobnosti mezi případy, a je tedy založen na analogii. A posledním, čtvrtým typem argumentu kluzkého svahu, kterému se příspěvek věnuje, je tzv. plný argument kluzkého svahu či kombinovaný argument kluzkého svahu. (shrink)

As more and more sophisticated software is created to allow the mining of arguments from natural language texts, this paper sets out to examine the suitability of the well-established and readily available methods of corpus linguistics to the study of argumentation. After brief introductions to corpus linguistics and the concept of meta-argument, I describe three pilot-studies into the use of the terms Straw man, Ad hominem, and Slippery slope, made using the open access News on the Web corpus. The presence (...) of each of these phrases on internet news sites was investigated and assessed for correspondence to the norms of use by argumentation theorists. All three pilot-studies revealed interesting facts about the usage of the terms by non-specialists, and led to numerous examples of the types of arguments mentioned. This suggests such corpora may be of use in two different ways: firstly, the wider project of improving public debate and educating the populace in the skills of critical thinking can only be helped by a better understanding of the current state of knowledge of the technical terms and concepts of argumentation. Secondly, theorists could obtain a more accurate picture of how arguments are used, by whom, and to what reception, allowing claims on such matters to be evidence, rather than intuition, based. (shrink)

This paper compares current ways of modeling the inferential structure of practical reasoning arguments, and proposes a new approach in which it is regarded in a modular way. Practical reasoning is not simply seen as reasoning from a goal and a means to an action using the basic argumentation scheme. Instead, it is conceived as a complex structure of classificatory, evaluative, and practical inferences, which is formalized as a cluster of three types of distinct and interlocked argumentation schemes. Using two (...) real examples, we show how applying the three types of schemes to a cluster of practical argumentation allows an argument analyst to reconstruct the tacit premises presupposed and evaluate the argumentative reasoning steps involved. This approach will be shown to overcome the limitations of the existing models of practical reasoning arguments within the BDI and commitment theoretical frameworks, providing a useful tool for discourse analysis and other disciplines. In particular, applying this method brings to light the crucial role of classification in practical argumentation, showing how the ordering of values and preferences is only one of the possible areas of deep disagreement. (shrink)

Although studies have yielded a detailed taxonomy of types of slippery slope arguments, they have failed to identify a basic argumentation scheme that applies to all. Therefore, there is no way of telling whether a given argument is a slippery slope argument or not. This paper solves the problem by providing a basic argumentation scheme. The scheme is shown to fit a clear and easily comprehensible example of a slippery slope argument that strongly appears to be reasonable, something that has (...) also been lacking. (shrink)

Implicatures are described as particular forms reasoning from best explanation, in which the para-digm of possible explanations consists of the possible semantic interpretations of a sentence or a word. The need for explanation will be shown to be triggered by conflicts between presumptions, namely hearer’s dialogical expectations and the presumptive sentence meaning. What counts as the best explanation can be established on the grounds of hierarchies of presumptions, dependent on dialogue types and interlocutors’ culture.

semantic minimalism and moderte contextualism.

Informal logic began in the 1970s as a critique of then-current theoretical assumptions in the teaching of argument analysis and evaluation in philosophy departments in the U.S. and Canada. The last 35 years have seen significant developments in informal logic and critical thinking theory. The paper is a pilot study of the influence of these advances in theory on what is taught in courses on argument analysis and critical thinking in U.S. and Canadian philosophy departments. Its finding, provisional and much-qualified, (...) is that the theoretical developments and refinements have had limited impact on instruction in leading philosophy departments. (shrink)

The essence of the argument of the beard (so-called by some logic textbooks) is the tactic used by a respondent to reply to a proponent, "The criterion you used to define a key term in your argument is vague, therefore your use of this term in your argument is illegitimate, and your argument is refuted." This familiar kind of argument tactic is similar to the much more famous heap (sorites) argument of Eubulides, closely associated with the slippery slope argument. This (...) article provides a system of classification for sorting out these three arguments, and related types of argument of interest in informal logic. (shrink)

The detection of hate speech and fake news in political discourse is at the same time a crucial necessity for democratic societies and a challenge for several areas of study. However, most of the studies have focused on what is explicitly stated: false article information, language that expresses hatred, derogatory expressions. This paper argues that the explicit dimension of manipulation is only one – and the least problematic – of the risks of political discourse. The language of the unsaid is (...) much more dangerous and incomparably more difficult to detect, hidden in different types of fallacies and inappropriate uses of emotive language. Through a threefold coding scheme based on the instruments of argumentation theory and pragmatics, a corpus of argumentative tweets published by 4 politicians (Matteo Salvini, Donald Trump, Jair Bolsonaro, and Joseph Biden) within 6 months from their taking office (corresponding to the official end of their election campaign) is analyzed, detecting the types of argument, the fallacies, and the uses and misuses of “emotive words.” This coding results in the argumentation profiles of the speakers, which are compared statistically to show their different implicit strategies and deceptive tactics. (shrink)

The article develops and justifies, on the basis of the epistemological argumentation theory, two central pieces of the theory of evaluative argumentation interpretation: 1. criteria for recognizing argument types and 2. rules for adding reasons to create ideal arguments. Ad 1: The criteria for identifying argument types are a selection of essential elements from the definitions of the respective argument types. Ad 2: After presenting the general principles for adding reasons (benevolence, authenticity, immanence, optimization), heuristics are proposed for finding missing (...) reasons, for deductive arguments, e.g., semantic tableaux are suggested. (shrink)

We examine in detail three classic reasoning fallacies, that is, supposedly ``incorrect'' forms of argument. These are the so-called argumentam ad ignorantiam, the circular argument or petitio principii, and the slippery slope argument. In each case, the argument type is shown to match structurally arguments which are widely accepted. This suggests that it is not the form of the arguments as such that is problematic but rather something about the content of those examples with which they are typically justified. This (...) leads to a Bayesian reanalysis of these classic argument forms and a reformulation of the conditions under which they do or do not constitute legitimate forms of argumentation. (shrink)

This paper begins a working through of Blair’s (2001) theoretical agenda concerning argumentation schemes and their attendant critical questions, in which we propose a number of solutions to some outstanding theoretical issues. We consider the classification of schemes, their ultimate nature, their role in argument reconstruction, their foundation as normative categories of argument, and the evaluative role of critical questions.We demonstrate the role of schemes in argument reconstruction, and defend a normative account of their nature against specific criticisms due to (...) Pinto (2001). Concerning critical questions, we propose an account on which they are founded in the R.S.A. cogency standard, and develop an account of the relationship between critical questions and burden of proof. Our ultimate aim is to initiate a reconciliation between dialectical and informal logic approaches to the schemes. (shrink)

In this article, transhumanism is considered to be a quasi-medical ideology that seeks to promote a variety of therapeutic and human-enhancing aims. Moderate conceptions are distinguished from strong conceptions of transhumanism and the strong conceptions were found to be more problematic than the moderate ones. A particular critique of Boström’s defence of transhumanism is presented. Various forms of slippery slope arguments that may be used for and against transhumanism are discussed and one particular criticism, moral arbitrariness, that undermines both weak (...) and strong transhumanism is highlighted. (shrink)

This paper discusses a novel kind of argument for assessing the moral significance of acts of lying and misleading. It is based on considerations about valuable social norms that might be eroded by these actions, because these actions function as signals. Given that social norms can play an important role in supporting morality, individuals have a responsibility to preserve such norms and to prevent ‘cultural slopes’ that erode them. Depending on whether there are norms against lying, misleading, or both, and (...) how likely it is that they might be eroded, these actions can thus have different moral significance. In cases in which the rule ‘do not lie’, as a relatively simple rule, functions as a ‘focal point’, acts of misleading are often morally preferable. In other words, in such cases the possibility of ‘cultural slopes’ can ground a context-dependent slippery slope argument for a moral difference between lying and misleading. (shrink)

Most arguments can be presented in different forms, e.g. with explicit data or with an explicit inference license and, in the latter case, with a modus ponens- or a modus tollens-inference license. It is arguable that one form is more appropriate or effective with regard to a specific piece of argumentation than another. However, in this paper it is argued that with regard to analogical reductio ad absurdum argumentation, its alleged persuasive effect is due to a successful appeal to common (...) ground and not to its form. (shrink)

Abstract This paper addresses the role that argumentation schemes and argument visualization software tools can play in helping to find and counter objections to a given argument one is confronted with. Based on extensive analysis of features of the argumentation in these two examples, a practical four-step method of finding objections to an argument is set out. The study also applies the Carneades Argumentation System to the task of finding objections to an argument, and shows how this system has some (...) capabilities that are especially useful. Content Type Journal Article Pages 1-23 DOI 10.1007/s10503-012-9261-z Authors Douglas Walton, Centre for Research in Reasoning, Argumentation and Rhetoric (CRRAR), University of Windsor, 2500 University Ave. W., Windsor, ON N9B 3Y1, Canada Journal Argumentation Online ISSN 1572-8374 Print ISSN 0920-427X. (shrink)

In Fallacies and Judgments of Reasonableness, Frans H. van Eemeren, Bart Garssen and Bert Meuffels report on their systematic empirical research of the conventional validity of the pragma-dialectical discussion rules. The experimental studies they carried out during more than ten years start from the pragma-dialectical theory of argumentation developed at the University of Amsterdam, their home university. In these studies they test methodically the intersubjective acceptability of the rules for critical discussion proposed in this theory by confronting ordinary arguers who (...) have not received any special education in argumentation and fallacies with discussion fragments containing both fallacious and non-fallacious argumentative moves. The research covers a wide range of informal fallacies. In this way, the authors create a basis for comparing the theoretical reasonableness conception of pragma-dialectics with the norms for judging argumentative moves prevailing in argumentative practice. Fallacies and Judgments of Reasonableness provides a unique insight into the relationship between theoretical and practical conceptions of reasonableness, supported by extensive empirical material gained by means of sophisticated experimental research. (shrink)

This volume contains 12 papers addressed to researchers and advanced students in informal logic and related fields, such as argumentation, formal logic, and communications. Among the issues discussed are attempts to rethink the nature of argument and of inference, the role of dialectical context, and the standards for evaluating inferences, and to shed light on the interfaces between informal logic and argumentation theory, rhetoric, formal logic and cognitive psychology.

Addressing the slippery slope argument (SSA) in legal contexts from the perspective of pragma-dialectics, this paper elaborates the conditions under which an SSA-scheme instance is used reasonably (rather than fallaciously). We review SSA-instances in past legal decisions and analyze the basic legal SSA-scheme. By illustrating the institutional preconditions influencing the reasoning by which an SSA moves forward, we identify three sub-schemes (causal SSA, analogical SSA, and Sorites SSA). For each sub-scheme we propose critical questions, as well as four rules that (...) clarify when the SSA scheme is used reasonably. The institutional preconditions make the analogical SSA expectable in common law contexts; the Sorites SSA is expectable in civil law contexts; whereas the causal SSA is common to both contexts. This result should inform future work on the identification of typical argumentative patterns for the SSA in legal contexts. (shrink)

Is the Nazi euthanasia program a useful analogy for contemporary discussions of euthanasia? This paper explores the logic of slippery slope arguments with the Nazi analogy as a test case.

One prevalent type of slippery slope argument has the following form: (1) by doing some initial act now, we will bring it about that we subsequently do some more extreme version of this act, and (2) we should not bring it about that we do this further act, therefore (3) we should not do the initial act. Such arguments are frequently regarded as mistaken, often on the grounds that they rely on speculative or insufficiently strong empirical premises. In this article (...) I point out another location at which these arguments may go wrong: I argue that, in their standard form, the truth of their empirical premises constitutes evidence for the falsity of their normative premises. If we will, as predicted, do the further act in the future, this gives us at least a prima facie reason to believe that the performance of this further act would be good, and thus something we should try to bring about. I end by briefly assessing the dialectic implications of my argument. I delineate a subset of slippery slope arguments against which my objection may be decisive, consider how the proponents of such arguments may evade my objection by adding further premises, and examine the likely plausibility of these additional premises. (shrink)

Arguing that our attachment to Aristotelian modes of discourse makes a revision of their conceptual foundations long overdue, the author proposes the consideration of unacknowledged factors that play a central role in argument itself. These are in particular the subjective imprint and the dynamics of argumentation. Their inclusion in a four-dimensional framework and the focus on thesis validity allow for a more realistic view of our discourse practice. Exhaustive analyses of fascinating historical and contemporary arguments are provided. These range from (...) Columbus’s advocacy of the Western Passage to India, over the trial of King Louis XVI during the French Revolution, to today’s highly charged controversies surrounding euthanasia and embryo research. Excavating foundational issues such as the purpose of argument itself and the contested role of argument as a generator of knowledge, the book culminates in a discussion of the relationship between rationality and reasonableness and criticizes the restrictions of ‘rational’ argument relying on fixed logical, economic or cultural criteria that in reality are mutable. Here, a true, open argument requires the infusion of Paul Lorenzen’s principle of ‘transsubjectivity’, which recognizes but transcends the partiality of the individual and which can be seen in the pragmatic and expanding consensus that humanity can control itself to safeguard the future of a fragile, damaged world. (shrink)

Argumentation schemes are forms of reasoning that are fallible but correctable within a self-correcting framework. Their use provides a basis for taking rational action or for reasonably accepting a conclusion as a tentative hypothesis, but they are not deductively valid. We argue that teleological reasoning can provide the basis for justifying the use of argument schemes both in monological and dialogical reasoning. We consider how such a teleological justification, besides being inspired by the aim of directing a bounded cognizer to (...) true belief and correct choices, needs to take into account the attitudes of dialogue partners as well as normative models of dialogue and communicative activity types, in particular social and cultural settings. (shrink)

In Swiss semi-direct democracy, citizens are often summoned to the polls. To vote reasonably, they need to be properly informed. The media therefore have the responsibility to provide them with arguments for and against each issue of voting. Here, we focus on argumentation in a television ‘civic debate’ about abolishing compulsory military service. To provide a unified and integrated overview of the debate dynamics, we combine the Dialogical Model of Argumentation and the Argumentum Model of Topics, which share a similar (...) emphasis on the discursive dimension of argumentation. This analysis underlines the importance of linguistic and communicative resources and procedures, without neglecting the macro socio-political environment of the debate. (shrink)

This chapter contains sections titled: An Example The Paradigmatic Form of the Argument The Appeal to a Pernicious Precedent Slopes of Reason Slopes of Unreason Factual and Moral Plausibility Appearance and Reality References.

The Nature and Status of Critical Questions in Argumentation Schemes.

Der Beitrag befasst sich mit den Chancen und Risiken einer allfälligen gesetzlichen Legalisierung der Suizidbeihilfe. Die Argumente, die gegen eine solche Legalisierung sprechen, werden zu drei thematischen Gruppen zusammengefasst und erörtert: „Slippery-Slope“-Argumente, Argumente vom „moralischen Druck“, und die Furcht vor einer „Entsolidarisierung der Gesellschaft“ sowie die „Gefährdung des Arzt-Patient-Verhältnisses“. Diese Gegenargumente erweisen sich als nicht zwingend, sofern Kriterien und Richtlinien für eine legitime Form der Suizidbeihilfe entwickelt und staatlich kontrolliert werden könnten.

This article applies tools from argumentation theory to slippery slope arguments used in current ethical debates on genetic engineering. Among the tools used are argumentation schemes, value-based argumentation, critical questions, and burden of proof. It is argued that so-called drivers such as social acceptance and rapid technological development are also important factors that need to be taken into account alongside the argumentation scheme. It is shown that the slippery slope argument is basically a reasonable form of argument, but is often (...) flawed when used in ethical debates because of failures to meet the requirements of its scheme. (shrink)

This study tests how various kinds of trust impact attitudes toward euthanasia among the general public. The indication that trust might have an impact on euthanasia attitudes is based on the slippery slope argument, which asserts that allowing euthanasia might lead to abuses and involuntary deaths. Adopting this argument usually leads to less positive attitudes towards euthanasia. Tying in with this, it is assumed here that greater trust diminishes such slippery slope fears, and thereby increases euthanasia acceptance.

Is there any reason to discriminate among the rival claims self-proclaimed conservatives make for being truly conservative? This article argues that at least some of these claims can legitimately be dismissed by an independent third. Drawing on and critically interrogating the theories of conservatism provided by Huntington, Oakeshott, as well as Brennan and Hamlin, this article argues that many characterizations of conservatism mistake contingent circumstances explaining why people historically were or conceivably might be reluctant to promote social change for a (...) fully-formed conservative ideology. Not least, risk- and uncertainty-centred accounts, which have gained in popularity as of recently, constitute no viable basis for plausible claims to being truly conservative. Rather than specifying what it takes to be a true conservative, these accounts provide a formalized description of one kind of contingent circumstances that may lead a principled non-conservative to adopt conservative political attitudes. (shrink)

Used informally, the Reductio ad Absurdum (RAA) consists in reasoning appealing to the logically implied, absurd consequences of a hypothetical proposition, in order to refute it. This kind of reasoning resembles the Argument from Consequences, which appeals to causally induced consequences. These types of argument are sometimes confused, since it is not worked out how these different kinds of consequences should be distinguished. In this article it is argued that the logical consequences in RAA-argumentation can take different appearances and that (...) it therefore must be concluded that RAA cannot be characterised by a specific content, but must instead be characterised as an argument form. Furthermore, clues are provided to distinguish RAA reasoning from the Argument from Consequences. (shrink)

Ethological farm programs as they exist in Switzerland are compared with environmental farm programs in respect of demand and supply. Because animal welfare is not a public good but rather a relation that causes psychological externalities, the demand for animal welfare has a different standing in economic theory than the demand for a clean environment. The supply of animal welfare by farmers, however, largely follows the patterns known from the delivery of environmental goods. Farm size, age and education, and also (...) family size and capital intensity are influencing variables. The paper concludes that the design of ethological farm programs should be based on broad public discussions as described by deliberation theorists rather than willingness-to-pay studies. (shrink)

The aims of this paper are to illustrate where previous attempts at the characterisation of slippery slope arguments have gone wrong, to provide an analysis which better captures their true nature, and to show the importance of achieving a clear definition which distinguishes this argument structure from other forms with which it may be confused. The first part describes the arguments of Douglas Walton and others, which are found wanting due to their failure to capture the essence of the slippery (...) slope and their inability to distinguish SSAs from other consequentialist forms of argument. The second part of the paper puts forward a clear analysis of what is special about SSAs: it is argued that all SSAs, properly so-named, claim that reaching a certain conclusion, A, involves the negation of a thitherto accepted principle, P, and that that principle is necessary to argue against further conclusions which are considered unacceptable. (shrink)

ABSTRACT Pharmacogenetics is a rapidly expanding area of research exploring the relationship between inter‐individual genetic variation and drug response, with the goal of developing genetically optimised therapies. Slippery slope arguments claim that a particular action should be rejected (or supported) because it might be the first step onto a slippery slope leading to undesirable (or desirable) consequences. In this article, several slippery slope arguments relevant to the context of pharmacogenetics are evaluated under consideration of underlying reasons for their popularity. The (...) author concludes that although the examined arguments are unconvincing as slippery slope arguments, they do matter in this context. While positive slippery slope arguments serve as a driving force to fuel the development of pharmacogenetics, their negative counterparts play an important role to sensitise policy makers and the public to potential problems. (shrink)

This article seeks to assess the results of legislation legalizing medical termination, known in Canada as "medical aide in dying" in 2016. Its focus, like that of previous authors, is to ask if the concerns of skeptics opposed to legalization have been realized or were they unfounded. These include the likelihood of a “slippery slope” with an expanding definition of eligibility and of MAiD deaths. Of similar concern at least since 1995 was the likelihood that, in the absence of the (...) provision of palliative, rehabilitative, psychological and social services that medical termination would be a substitute for good medical care. These and other concerns are the basis for the review of MAiD in Canada clinically, legally and as an ethical construct. (shrink)

The article investigates the validity of two different versions of the slippery slope argument construed in relation to human gene therapy: the empirical and the conceptual argument. The empirical version holds that our accepting somatic cell therapy will eventually cause our accepting eugenic medical goals. The conceptual version holds that we are logically committed to accepting such goals once we have accepted somatic cell therapy. It is argued that neither the empirical nor the conceptual version of the argument can provide (...) a conclusive moral reason for banning somatic cell therapy. According to a third interpretation, referred to as the arbitrary result argument, the many apparent similarities between somatic cell therapy and eugenic-based human genetic engineering drive us to make principled choices concerning what differences and similarities between the two practices should be regarded as morally (ir)relevant. Decisions of this kind are likely to have unpredictable moral consequences. Thus formulated, the slippery slope argument has much plausibility. One objects to somatic cell therapy not so much because of what is at the bottom of the slope on which it lies, but because it is on a slope of which one does not know what is at the bottom. While the arbitrary result argument does not provide a conclusive reason for prohibiting human gene therapy, it reminds of a very important thing: when making bioethical decisions, we should be as specific and as consistent as possible about our basic moral and medical concepts. (shrink)