Material traces of the past are notoriously inscrutable; they rarely speak with one voice, and what they say is never unmediated. They stand as evidence only given a rich scaffolding of interpretation which is, itself, always open to challenge and revision. And yet archaeological evidence has dramatically expanded what we know of the cultural past, sometimes demonstrating a striking capacity to disrupt settled assumptions. The questions we address in Evidential Reasoning are: How are these successes realized? What gives us (...) confidence in the credibility and robustness, the trustworthiness, of the evidential claims based on archaeological data? And, what constitute best practices in building evidential claims, critically scrutinizing them and putting them to work in archaeological contexts? Rather than retreat to abstractions about how how science operates in the ideal, we approach this question by interrogating a number of close-to-the-ground case studies with the aim of teasing out the wisdom embodied in archaeological practice. The cases we consider – of fieldwork, strategies for working with old evidence, and the role of external resources – illuminate the role of various types of inferential scaffolding and bring into focus practice-grounded epistemic norms that we believe serve archaeologists better than the all-or-nothing ideals of truth and objectivity that dominate programmatic debate. (shrink)

This article is a study of the role and use of evidence in the evaluation of claims in the historical sciences. In order to do this, I develop a “snapshot” approach to Toulmin schemas. This framework is applied to the case of Archezoa, an initially supported then eventually rejected hypothesis in evolutionary biology. From this case study, I criticize Cleland’s “smoking gun” account of the methodology of the historical sciences. I argue that Toulmin schemas are conceptually precise tools that allow (...) for the building of enriched reconstructions of evidential reasoning. From the application of this framework, I discuss three ways in which the construction and use of facts in the historical sciences are theory-laden. Despite its inherent limits, TS are heuristically useful tools to identify epistemic moves that could be further investigated. It also sheds light on the positive roles of speculation in the historical sciences. Finally, I argue that it provides a context-specific and individuated understanding of hypothesis evaluation in the historical sciences. Overall, I think the application of Toulmin schemas to cases of evidential reasoning in the historical sciences is a promising descriptive and heuristic tool for philosophers of science. (shrink)

The primary aim of this chapter is to explain the nature of evidential reasoning, the characteristic difficulties encountered, and the tools to address these difficulties. Our focus is on evidential reasoning in criminal cases. There is an extensive scholarly literature on these topics, and it is a secondary aim of the chapter to provide readers the means to find their way in historical and ongoing debates.

Eva Schmidt argues that facts about incoherent beliefs can be non-evidential epistemic reasons to suspend judgment. In this commentary, I argue that incoherence-based reasons to suspend are epistemically superfluous: if the subjects in Schmidt’s cases ought to suspend judgment, then they should do so merely on the basis of their evidential reasons. This suggests a more general strategy to reduce the apparent normativity of coherence to the normativity of evidence. I conclude with some remarks on (...) the independent interest that reasons-first epistemology might have within an evidentialist framework. (shrink)

Sometimes a belief that p promotes having true beliefs, whether or not p is true. This gives reasons to believe that p, but most epistemologists would deny that it gives epistemic reasons, or that these reasons can epistemically justify the belief that p. Call these reasons to believe “truth promoting non-evidential reasons for belief.” This paper argues that three common views in epistemology, taken together, entail that reasons of this sort can epistemically justify (...) beliefs. These three claims are: epistemic oughts are normative, epistemic oughts have a source, and the source of epistemic oughts is an end that has true belief as a necessary component. These claims would be hard for many epistemologists to deny, but accepting them, and thus accepting that truth promoting non-evidential reasons can justify beliefs, has significant consequences for epistemology. The paper considers accounts of epistemic oughts that endorse these claims but might seem to avoid the consequence that truth promoting non-evidential reasons generate real epistemic oughts, and shows that none do. (shrink)

In this paper I argue that we can give a plausible account of how to compare pragmatic and evidential normative reasons for belief. The account I offer is given in the form of a ‘defeasing function’. This function allows for a sophisticated comparison of the two types of reasons without assigning complex features to the logical structures of either type of reason.

Stephen Kearns and Daniel Star have made the following interesting proposal concerning the relation between practical reasons and evidence : Necessarily: A fact F is a reason for you to φ iff F is evidence that you ought to φ We're not sure about this. Although moving from left to right might be OK, the converse is problematic. For example, the fact that your reliable friend told you that you have overriding moral reason to φ is ….

Interpersonalist theories of testimony have the theoretical virtue of giving room to the characteristic interpersonal features of testimonial exchange among persons. Nonetheless, it has been argued that they are at a serious disadvantage when it comes to accounting for the way in which testimonial beliefs may be epistemically justified. In this paper, we defend the epistemological credentials of interpersonalism, emphasizing that it is inseparable from the acceptance of non-evidential epistemic reasons to believe, which demands proper conceptual elaborations on (...) the notions of epistemic reasons and of epistemic justification. We offer a proper reading of epistemic reason, and we defend non-purism on justification as the adequate way to conceive the epistemic proposal of interpersonalism on testimony, realizing that only this combination is capable of apprehending certain cases in which there seems to be no way to rule out the idea that the assurance offered by the testifier offers an epistemic reason to believe that it is not evidential. (shrink)

This article discusses the concept of evidential reasoning in the context of qualitative research methods in the social sciences. A conceptualization of qualitative evidential reasoning is proposed...

Evidential reasoning is hard, and errors can lead to miscarriages of justice with serious consequences. Analytic methods for the correct handling of evidence come in different styles, typically focusing on one of three tools: arguments, scenarios or probabilities. Recent research used Bayesian networks for connecting arguments, scenarios, and probabilities. Well-known issues with Bayesian networks were encountered: More numbers are needed than are available, and there is a risk of misinterpretation of the graph underlying the Bayesian network, for instance as (...) a causal model. The formalism presented here models presumptive arguments about coherent hypotheses that are compared in terms of their strength. No choice is needed between qualitative or quantitative analytic styles, since the formalism can be interpreted with and without numbers. The formalism is applied to key concepts in argumentative, scenario and probabilistic analyses of evidential reasoning, and is illustrated with a fictional crime investigation example based on Alfred Hitchcock’s film ‘To Catch A Thief’. (shrink)

This chapter suggests that evidence should be viewed as a field of study, one to which most disciplines could contribute and from which most could benefit, and that generalisations should be viewed as part of that field. Every argument must be based upon a generalisation that can be stated as a major premise. The relationship between a supporting proposition or propositions and an inferred proposition can be restated in a quasi-deductive form by identifying the generalisation upon which the inference depends. (...) A datum or a proposition can be evidence if and only if it alters the probability, positively or negatively, of a proposition to be inferred. In order to demonstrate that an evidential proposition is relevant, an analyst must be able to identify and articulate a generalisation that justifies the claim that the evidential proposition alters the probability of an inferred proposition. This chapter develops these ideas and presents a method of generalisation-analysis. It also argues that generalisation-analysis is a tool in the field of evidence that could be useful in analysing and critiquing arguments in many disciplines. (shrink)

(2013). Legal idioms: a framework for evidential reasoning. Argument & Computation: Vol. 4, Formal Models of Reasoning in Cognitive Psychology, pp. 46-63. doi: 10.1080/19462166.2012.682656.

When the likelihood ratio approach is employed for evidential reasoning in law, it is often necessary to employ subjective probabilities, which are probabilities derived from the opinions and judgement of a human. At least three concerns arise from the use of subjective probabilities in legal applications. Firstly, human beliefs concerning probabilities can be vague, ambiguous and inaccurate. Secondly, the impact of this vagueness, ambiguity and inaccuracy on the outcome of a probabilistic analysis is not necessarily fully understood. Thirdly, the (...) provenance of subjective probabilities and the associated potential sources of vagueness, ambiguity and inaccuracy tend to be poorly understood, making it difficult for the outcome of probabilistic reasoning to be explained and validated, which is crucial in legal applications. The former two concerns have been addressed by a wide body of research in AI. The latter, however, has received little attention. This paper presents a novel approach to employ argumentation to reason about probability distributions in probabilistic models. It introduces a range of argumentation schemes and corresponding sets of critical questions for the construction and validation of argument models that define sets of probability distributions. By means of an extended example, the paper demonstrates how the approach, argumentation schemes and critical questions can be employed for the development of models and their validation in legal applications of the likelihood ratio approach to evidential reasoning. (shrink)

This dissertation examines the dynamical dark matter problem in twentieth century astrophysics from the point of view of History and Philosophy of Science. The dynamical dark matter problem describes the situation astronomers find themselves in with regard to the dynamics of large scale astrophysical systems such as galaxies and galaxy clusters: The observed motions are incompatible with the visible distribution matter given the accepted law of gravitation. This discrepancy has two classes of possible solutions: either there exists copious amounts of (...) some kind of matter that neither emits nor absorbs radiation , or the law of gravitation must be revised. ;Chapter 2 describes the physical and philosophical foundations of dynamical inferences---inferences from discrepancies between well-founded theoretical expectations and reliable observations to the characteristics of candidate solutions. Chapter 3 discusses the history of dark matter . Chapter 4 reviews the present evidence bearing on the dark matter problem. Chapter 5 evaluates the important candidate matter solutions in light of the available evidence. Chapter 6 evaluates two candidate gravitational solutions on evidential and methodological grounds, and addresses the problem of theory choice. I do not try to solve the dark matter problem, but to uncover and evaluate patterns of inference involved in evidential arguments for and against candidate solutions. ;I show that Newton's "Reasoning from Phenomena" is a good framework from which to understand what is going on in this field. I argue that "higher order" and especially non-dynamical evidence is the best hope for solving this problem in dynamics. This is so in part because of "the dark matter double bind": the very existence of the dark matter problem means that we cannot be sure of the overall matter distribution in astrophysical systems, and this in turn means that the observed motions by themselves cannot provide relative confirmation of any theory of gravitational interactions taking place at these scales. I use Newton's Rules of Reasoning to argue that we should retain General Relativity as our theory of gravity at galactic and greater scales, despite the lack of positive evidence to confirm it over its rivals at these scales. (shrink)

The First World Congress on Evidential Legal Reasoning, organised by the Legal Culture Chair of the University of Girona, was held between June 6 and 8, 2018. The Congress was attended by 350 participants and featured 18 speakers from four continents. The three days of formal and informal presentations and discussions yielded excellent results, strengthening the interrelation between the legal communities and specialists of different traditions. The 18 papers from the Congress, reviewed by their authors based on the discussions (...) and the suggestions made at the Congress, have been compiled in this book. (shrink)

A detailed treatment regarding the diverse properties and uses of evidence and the judgmental tasks they entail. Examines various processes by which evidence may be developed or discovered. Considers the construction of arguments made in defense of the relevance and credibility of individual items and masses of evidence as well as the task of assessing the inferential force of evidence. Includes over 100 numerical examples to illustrate the workings of diverse probabilistic expressions for the inferential force of evidence and the (...) subtleties they reveal. (shrink)

Most legal evidence scholars agree that proof of guilt beyond a reasonable doubt requires the belief that the defendant probably committed the alleged acts. However, they also agree that this is not a sufficient condition, as this belief may be unreasonable. I focus on two popular proposals for additional conditions: (i) that the degree of belief should be robust and (ii) that it should be reasonable given the available evidence (should be an evidential probability). Both criteria face difficulties regarding (...) their meaning and utility. I propose an interpretation which overcomes these difficulties and which combines the two conditions into a single criterion on which both conditions are about the possibility of overlooked, exculpatory information. Proof of guilt beyond a reasonable doubt requires that we are sufficiently certain that we did not miss such information for the sake of achieving accurate beliefs and a just error distribution. How certain we can be that we did not miss anything relevant depends on our higher-order evidence. One important type of higher-order evidence is whether the hypotheses under consideration are sufficiently detailed. This point leads to a novel way of combining the Bayesian and explanation-based accounts of rational legal proof. (shrink)

This book offers a transnational perspective of evidentiary problems, drawing on insights from different systems and legal traditions. It avoids the isolated manner of analyzing evidence and proof within each Common Law and Civil Law tradition. Instead, it features contributions from leading authors in the evidentiary field from a variety of jurisdictions and offers an overview of essential topics that are of both theoretical and practical interest. The collection examines evidence not only as a transnational field, but in a cross-disciplinary (...) context. Each chapter engages with the interdisciplinary themes cutting through the issues discussed, benefiting from the expertise and experience of their diverse authors. (shrink)

Beliefs can be evaluated from a number of perspectives. Epistemic evaluation involves epistemic standards and appropriate epistemic goals. On a truthconducive account of epistemic justification, a justified belief is one that serves the goal of believing truths and avoiding falsehoods. Beliefs are also prompted by nonepistemic reasons. This raises the question of whether, say, the pragmatic benefits of a belief are able to rationalize it. In this paper, after criticizing certain responses to this question, I shall argue that, as (...) far as beliefs are concerned, justification has an essentially epistemic character. This conclusion is then qualified by considering the conditions under which pragmatic consequences of a belief can be epistemically relevant. (shrink)

This paper presents an information-based logic that is applied to the analysis of entailment, implicature and presupposition in natural language. The logic is very fine-grained and is able to make distinctions that are outside the scope of classical logic. It is independently motivated by certain properties of natural human reasoning, namely partiality, paraconsistency, relevance, and defeasibility: once these are accounted for, the data on implicature and presupposition comes quite naturally.The logic is based on the family of semantic spaces known as (...) bilattices, originally proposed by Ginsberg (1988), and used extensively by Fitting (1989, 1992). Specifically, the logic is based on a subset of bilattices that I call evidential bilattices, constructed as the Cartesian product of certain algebras with themselves. The specific details of the epistemic agent approach of the logical system is derived from the work of Belnap (1975, 1977), augmented by the use of evidential links for inferencing. An important property of the system is that it has been implemented using an extension of Fitting's work on bilattice logic programming (1989, 1991) to build a model-based inference engine for the augmented Belnap logic. This theorem prover is very efficient for a reasonably wide range of inferences. (shrink)

In this paper, I respond to Frank Hofmann’s reply to my (2022) argument against “evidential minimalism” (EM). According to defenders of EM, there is a close connection between evidence and normative reasons for belief: evidence is either itself, or (under certain “minimal” conditions) gives rise to, a normative reason for belief. In my (2022), I argued against EM by showing that there are cases where: (i) S possesses strong evidence E for the truth of p at time t, (...) (ii) all minimal conditions for the normativity of E are met at t, (iii) S doesn’t believe p at t, yet (iv) S isn’t criticizable on account of (i)-(iii) at t. I then appealed to a linking claim connecting criticizability with the existence of normative reasons for belief. Hofmann’s reply invokes a distinction between two different kinds of epistemic criticism: a strong and a weak form. I will argue that Hofmann’s distinction fails to save EM from my argument. (shrink)

Bayesian networks (BN) and argumentation diagrams (AD) are two predominant approaches to legal evidential reasoning, that are often treated as alternatives to one another. This paper argues that they are, instead, complimentary and proposes the beginnings of a method to employ them in such a manner. The Bayesian approach tends to be used as a means to analyse the findings of forensic scientists. As such, it constitutes a means to perform evidential reasoning. The design of Bayesian networks that (...) accurately and comprehensively represent the relationships between investigative hypotheses and evidence remains difficult and sometimes contentious, however. Argumentation diagrams are representations of reasoning, and are used as a means to scrutinise reasoning (among other applications). In evidential reasoning, they tend to be used to represent and scrutinise the way humans reason about evidence. This paper examines how argumentation diagrams can be used to scrutinise Bayesian evidential reasoning by developing a method to extract argument diagrams from BN. (shrink)

We show in this paper that some expressions indicating source of evidence are part of propositional content and are best analyzed as special kind of epistemic modal. Our evidence comes from the Japanese evidential system. We consider six evidentials in Japanese, showing that they can be embedded in conditionals and under modals and that their properties with respect to modal subordination are similar to those of ordinary modals. We show that these facts are difficult for existing theories of evidentials, (...) which assign evidentials necessarily widest scope, to explain. We then provide an analysis using a logical system designed to account for evidential reasoning; this logic is the first developed system of probabilistic dynamic predicate logic. This analysis is shown to account for the data we provide that is problematic for other theories. (shrink)

the symmetry of our evidential situation. If our confidence is best modeled by a standard probability function this means that we are to distribute our subjective probability or credence sharply and evenly over possibilities among which our evidence does not discriminate. Once thought to be the central principle of probabilistic reasoning by great..

Once upon a time, some thought that indicative conditionals could be effectively analyzed as material conditionals. Later on, an alternative theoretical construct has prevailed and received wide acceptance, namely, the conditional probability of the consequent given the antecedent. Partly following critical remarks recently ap- peared in the literature, we suggest that evidential support—rather than conditional probability alone—is key to understand indicative conditionals. There have been motivated concerns that a theory of evidential conditionals (unlike their more tra- ditional counterparts) (...) cannot generate a sufficiently interesting logical system. Here, we will describe results dispelling these worries. Happily, and perhaps surprisingly, appropriate technical variations of Ernst Adams’s classical approach allow for the construction of a logic of evidential conditionals with distinctive fea- tures, which is also well-behaved and reasonably strong. (shrink)

This paper presents a counterexample to the principle that all epistemic reasons for doxastic attitudes towards p are provided by evidence concerning p. I begin by motivating and clarifying the principle and the associated picture of epistemic reasons, including the notion of evidence concerning a proposition, which comprises both first- and second-order evidence. I then introduce the counterexample from incoherent doxastic attitudes by presenting three example cases. In each case, the fact that the subject’s doxastic attitudes are incoherent (...) is an epistemic reason to suspend, which is not provided by evidence. I argue that this incoherence fact is a reason for the subject to take a step back and reassess her evidence for her conflicting attitudes, and thus a reason to suspend all of them. Suspending judgment enables the subject to revise attitudes where appropriate and thus (typically) to arrive at a set of coherent and well-supported attitudes. I then address a dilemma for my proposal and, in conclusion, briefly suggest a picture of epistemic reasons on which they are to be understood against the background of the subject’s virtuous intellectual conduct. (shrink)

We show in this paper that some expressions indicating source of evidence are part of propositional content and are best analyzed as special kind of epistemic modal. Our evidence comes from the Japanese evidential system. We consider six evidentials in Japanese, showing that they can be embedded in conditionals and under modals and that their properties with respect to modal subordination are similar to those of ordinary modals. We show that these facts are difficult for existing theories of evidentials, (...) which assign evidentials necessarily widest scope, to explain. We then provide an analysis using a logical system designed to account for evidential reasoning; this logic is the first developed system of probabilistic dynamic predicate logic. This analysis is shown to account for the data we provide that is problematic for other theories. (shrink)

Evidence is often taken to be “normative” for doxastic agents. What accounts for the normativity of evidence? According to the view that I’ll call “evidential minimalism”, there is a close connection between strong evidence for the truth of p and a normative reason to believe p: evidence is either itself a normative reason for belief, or evidence gives rise to such a reason when certain other minimal conditions are met. In this paper, I argue against evidential minimalism. I (...) will argue that there are cases where: (i) an individual S possesses strong evidence E for the truth of p at time t, (ii) all other minimal conditions for the normativity of E are met at t, (iii) S doesn’t believe p at t, yet (iv) S isn’t open to any form of criticism on account of (i)-(iii) at t. I will then formulate a plausible linking claim connecting openness to criticism and the existence of normative reasons for belief. The minimalist can either accept or reject this linking claim. I will argue that, either way, the minimalist view falters. (shrink)

Is evil evidence against the existence of God? Even if God and evil are compatible, it remains hotly contested whether evil renders belief in God unreasonable. The Evidential Argument from Evil presents five classic statements on this issue by eminent philosophers and theologians and places them in dialogue with eleven original essays reflecting new thinking by these and other scholars. The volume focuses on two versions of the argument. The first affirms that there is no reason for God to (...) permit either certain specific horrors or the variety and profusion of undeserved suffering. The second asserts that pleasure and pain, given their biological role, are better explained by hypotheses other than theism. -/- Contributors include William P. Alston, Paul Draper, Richard M. Gale, Daniel Howard-Snyder, Alvin Plantinga, William L. Rowe, Bruce Russell, Eleonore Stump, Richard G. Swinburne, Peter van Inwagen, and Stephen John Wykstra. (shrink)

The setting of evidential standards is a core practice of scientific assessment for policy. Persuaded by considerations of inductive risk, philosophers generally agree that the justification of evidential standards must appeal to non-epistemic values but debate whether the balance of non-epistemic reasons favours varying evidential standards versus maintaining fixed high evidential standards in assessment, as both sets of standards promote different and important political virtues of advisory institutions. In this paper, I adjudicate the evidential (...) standards debate by developing a novel argument from justice, drawing on the IPCC’s assessment of climate impacts as a case study. I argue that in assessments marked by background evidential inequality, maintaining fixed high evidential standards results in an unequal distribution of ‘epistemic power’ among stakeholders, producing a ‘powerful assessment’ for the data-rich (a high rate of findings) and a ‘weak assessment’ for the data-poor (a low rate of findings). Where such inequalities of epistemic power disadvantage those in data-poor regions with respect to fundamental interests, such as basic human rights, we have decisive reasons of justice to vary evidential standards. (shrink)

This paper develops an analysis of a scalar implicature that is induced by the use of reportative evidentials such as the Cuzco Quechua enclitic = si and the German modal sollen. Reportatives, in addition to specifying the speaker’s source of information for a statement as a report by someone else, also usually convey that the speaker does not have direct evidence for the proposition expressed. While this type of implicature can be calculated using the same kind of Gricean reasoning that (...) underlies other scalar implicatures, it requires two departures from standard assumptions. First, evidential scalar implicatures differ from the more familiar scalar implicatures in that they do not turn on the notion of informativeness but on the notion of evidential strength. Second, the implicature arises on the illocutionary level of meaning. It is argued that a version of Grice’s maxim of quantity in terms of illocutionary strength can account for this evidential scalar implicature as well as for the more typical scalar implicatures. The account developed also proposes some revisions to the taxonomy of speech acts and suggests that the sincerity conditions of assertive speech acts contain an evidential sincerity condition in addition to the belief condition standardly assumed. (shrink)

The indispensability argument is a method for showing that abstract mathematical objects exist. Various versions of this argument have been proposed. Lately, commentators seem to have agreed that a holistic indispensability argument will not work, and that an explanatory indispensability argument is the best candidate. In this paper I argue that the dominant reasons for rejecting the holistic indispensability argument are mistaken. This is largely due to an overestimation of the consequences that follow from evidential holism. Nevertheless, the (...) holistic indispensability argument should be rejected, but for a different reason —in order that an indispensability argument relying on holism can work, it must invoke an unmotivated version of evidential holism. Such an argument will be unsound. Correcting the argument with a proper construal of evidential holism means that it can no longer deliver mathematical Platonism as a conclusion: such an argument for Platonism will be invalid. I then show how the reasons for rejecting the holistic indispensability argument importantly constrain what kind of account of explanation will be permissible in explanatory versions. (shrink)

The _Principle of Indifference_ was once regarded as a linchpin of probabilistic reasoning, but has now fallen into disrepute as a result of the so-called _problem of multiple of partitions_. In ‘Evidential symmetry and mushy credence’ Roger White suggests that we have been too quick to jettison this principle and argues that the problem of multiple partitions rests on a mistake. In this paper I will criticise White’s attempt to revive POI. In so doing, I will argue that what (...) underlies the problem of multiple partitions is a fundamental tension between POI and the very idea of _evidential incomparability_. (shrink)

The vagaries of evidential reasoning in archaeology are notorious: the material traces that comprise the archaeological record are fragmentary and profoundly enigmatic, and the inferential gap that archaeologists must cross to constitute them as evidence of the cultural past is a peren­nial source of epistemic anxiety. And yet we know a great deal about the cultural past, including vast reaches of the past for which this material record is our only source of evidence. The contents of this record stand (...) as evidence only under interpretation, but however much a construct it is, archaeological evidence has a striking capacity to disrupt settled assump­tions, redirecting inquiry and expanding interpretive horizons in direc­tions no one could have anticipated. It is this capacity for constraining inference and interpretation that I am concerned to understand. I outline a model of evidential reasoning based on archaeological practice that integrates insights drawn from philosophical theories of confirmation, model building and hypothesis testing. Given growing interest in the uses of material evidence in fields that had been resolutely text-based, the archaeological principles of evidential reasoning may have much wider reach than this particular social/historical discipline. (shrink)

The article argues for the epistemic rationale of triangulation, namely, the use of multiple and independent sources of evidence. It claims that triangulation is to be understood as causal reasoning from data to phenomenon, and it rationalizes its epistemic value in terms of controlling for likely errors and biases of particular data-generating procedures. This perspective is employed to address objections against triangulation concerning the fallibility and scope of the inference, as well as problems of independence, incomparability, and discordance of evidence. (...) The debate on the existence of social preferences is used as an illustrative case. (shrink)

This contribution aims at providing an argumentative method to account for epistemic modality and evidentiality. I claim that these two linguistic categories can work as semantic components of defeasible argumentative schemes based on classification processes. This kind of approximate reasoning is, in fact, frequently indicated by appearance verbs which signal that the inferred standpoint is conceived by the speaker as uncertain due to the deceiving nature of perceptual data. Drawing from an analysis at the semantic-argumentative interface, the way in which (...) prototype theory sheds light on the processes of meaning construction underlying defeasible arguments from definition is also shown. (shrink)