Cognitive scientists used to deem reasoning either as a higher cognitive process based on the manipulation of abstract rules or as a higher cognitive process that is stochastic rather than involving abstract rules. I maintain that these different perspectives are closely intertwined with a theoretical and methodological endorsement of either cognitivism or connectionism. Cognitivism and connectionism represent two prevailing and opposed paradigms in cognitive science. I aim to extoll the virtues of connectionist models of enthymematic reasoning by following means: via (...) the phenomenon of creative enthymeme, viz. the inference where one cannot even articulate the missing premise, I introduce a connectionist mechanism of pattern recognition as underlying expertise; via Gestalt switch or Gestalt click, I demonstrate how differences in pattern recognition of an expert and a novice can be construed as qualitatively different, and not merely a matter of faster reasoning. (shrink)

Which properties are characteristic of the enthymeme in Aristotle's Rhetoric? There is no consensus on this point. The present discussion centres on three properties. 1. Is there always an implicit premise? (Answer: Above all, a pragmatic level and a logical level must be distinguished.) 2. Do the premises consist by definition of probabilities and signs? (Answer: No.). 3. Are all enthymemes reducible to a syllogistic form? (Answer: The literature pertaining to this question is dominated by a false dilemma: an (...) enthymeme does not have either a topical or a syllogistic structure). In general, Aristotle's approach to the enthymeme in the Rhetoric appears to shift from argumentation theory to logic. (shrink)

How to use truth tables to narrow down the number of possible candidates for missing premise. and, how to use philosophical analysis to pick the most plausible candidate from among those. this activity is a nice capstone to a course in logic for it combines formal and informal procedures.

The Legacy of Aristotelian Enthymeme provides a historical-logical analysis of Aristotle's rhetorical syllogism, the enthymeme, through its Medieval and Renaissance interpretations. Bringing together notions of credibility and proof, an international team of scholars highlight the fierce debates around this form of argumentation during two key periods for Aristotle's beliefs.Reflecting on medieval and humanist thinkers, philosophers, poets and theologians, this volume joins up dialectical and rhetorical argumentation as key to the enthymeme's interpretation and shows how the enthymeme (...) was the source of a major interpretive conflict. As a method for achieving the standards for proof and credibility that persist across diverse fields of study today including the law, politics, medicine and morality, this book takes in Latin and Persian interpretations of the enthymeme and casts contemporary argumentation in a new historical light. (shrink)

In Enthymemes and Topoi in Dialogue, Ellen Breitholtz presents a novel and precise account of reasoning from an interactional perspective. The account draws on the concepts of enthymemes and topoi, originating in Aristotelian rhetoric and dialectic, and integrates these in a formal dialogue semantic account using TTR, a type theory with records. Argumentation analysis and formal approaches to reasoning often focus the logical validity of arguments on inferences made in discourse from a god's-eye perspective. In contrast, Breitholtz's account emphasises the (...) individual perspectives of interlocutors and the function and acceptability of their reasoning in context. This provides an analysis of interactions where interlocutors have access to different topoi and therefore make different inferences. (shrink)

Examines the concept of the enthymeme in ancient Greek rhetoric, arguing that it is a technique of storytelling aimed at eliciting from the audience an inference about a narrative.

In lieu of an abstract, here is a brief excerpt of the content:Philosophy and Rhetoric 34.2 (2001) 93-112 [Access article in PDF] Enthymemes, Common Knowledge, and Plausible Inference Douglas Walton The study of enthymemes has always been regarded as important in logic, critical thinking, and rhetoric, but too often it is the formal or mechanistic aspect of it that has been in the forefront. This investigation will show that there is a kind of plausibilistic script-based reasoning, of a kind (...) that has mainly been studied in artificial intelligence, that should have a much more important role to play in the study of enthymemes. But then curiously, as will also be shown, this plausibilistic type of reasoning was familiar in the ancient world, to the Sophists, as well as to leading philosophers such as Plato and Aristotle. By linking this ancient notion of plausibility to the modern notion used in computer science, this investigation reveals an important basis for the enthymeme that has a type of logical structure in its own right, but also has an informal aspect.An enthymeme, in current usage, is an argument that has one or more premises, or possibly a conclusion, not explicitly stated in the text, but that needs to have these propositions explicitly stated to extract the complete argument from the text. Sometimes enthymemes are described as arguments with "missing premises." That vocabulary is awkward, however, because the nonexplicit statement that needs to be added can be a conclusion, at least in a minority of cases. To make the exposition below smoother, the term nonexplicit assumption will be used to cover either the case of a nonexplicit premise or that of a nonexplicit conclusion. The problem with enthymemes is that if the nonexplicit assumptions in an argument are supposed to be propositions used by the arguer (as opposed to just the propositions needed to make the argument structurally correct, according to some standard), reasonable people can have differences of opinion on what the nonexplicit assumptions are supposed to be. The problem is that filling in the missing parts of enthymemes depends on interpreting the natural language [End Page 93] in which the argument was put forward to try to determine what the speaker meant to say.The solution to the problem comes through the recognition that enthymemes rest not only on formal (structural) criteria, but also on informal criteria. One of the most important of these informal criteria is something often called "common knowledge" (Govier 1992; Freeman 1995). But as shown below in a set of selected case studies of enthymemes, "common knowledge" is not really a kind of knowledge at all. It is really plausibility, or eikos, something well known in the ancient world and often misleadingly translated as "probability." Curiously, Aristotle's original doctrine of the enthymeme was based on this notion of plausibility. This historical fact has often been a source of puzzlement and confusion, and sometimes it has even been taken to indicate a defect or contradiction in Aristotle's treatment of the enthymeme. However, the goal of this investigation is not primarily historical. It is to work out one of the most important required steps toward a solution to the problem of enthymemes. But to do this, it is necessary to come back to the ancient notion of plausible inference. 1. The problem with enthymemes Once you have any formal theory of inference, like syllogistic, for example, you will be confronted by cases of arguments in everyday discourse that meet all the requirements for a structurally correct inference except that some part or parts, usually a premise or a conclusion, is missing. By "missing" is meant that the proposition in question has not been explicitly stated in the text of discourse, even though it may be clear enough that the speaker (writer) was relying on it, or including it, as part of the argument. The classic example is the following inference: All men are mortal; therefore, Socrates is mortal. To evaluate such an argument, surely some account of the "hidden" or "missing" assumption needs to be taken. The problem with enthymemes (Burke 1985; Gough and Tindale 1985; Hitchcock 1985) is that, if given carte... (shrink)

This paper argues for a reinterpretation of Aristotle's concept of an enthymeme and also his wider informal logic in terms of arguments that are defeasible. They are represented by forms of argument that are called argumentation schemes, considered to be similar to forms of argument found in deductive logic, but different from the foregoing in virtue of their being defeasible. Indeed, the most interesting schemes have been put forward as a helpful way of characterizing structures of human (...) reasoning that have proved troublesome to model deductively. The paper sheds new light on Aristotle's topics and how to dene `enthymeme'. If the traditional denition of an enthymeme in logic accepted for over two thousand years is a misnomer, the question is raised whether we ought to redene it as a defeasible argumentations scheme or leave things as they are. (shrink)

Positions in dialogic dispute are presented enthymematically. It is important to explore the position the disputant holds. A model is offered which relies on the presentation of a counter-example to an inferred missing premiss. The example may be: [A+J embraced as falling under the rule; [A-] rejected as basically changing the position; or, [R] rejected as changing the proffered missing premiss. In each case the offered model indicates the next appropriate action. The focus of the model is on uncovering the (...) position actually held by the disputant as opposed to identifying the "logically correct" enthymematic premiss. (shrink)

The enthymeme is essential because it reflects what humans do when they think. It provides an effective pedagogical approach to the analysis and synthesis of ideas in the classroom. In this volume, such an approach is applied to various areas of content for the purpose of helping students prepare themselves for the challenges of modern life.

The aim of this investigation is to explore the role of argumentation schemes in enthymeme reconstruction. This aim is pursued by studying selected cases of incomplete arguments in natural language discourse to see what the requirements are for filling in the unstated premises and conclusions in some systematic and useful way. Some of these cases are best handled using deductive tools, while others respond best to an analysis based on defeasible argumentations schemes. The approach is also shown to work (...) reasonably well for weak arguments, a class of arguments that has always been difficult to analyze without the principle of charity producing a straw man. (shrink)

The implicit dimension of enthymemes is investigated from a pragmatic perspective to show why a premise can be left unexpressed, and how it can be used strategically. The relationship between the implicit act of taking for granted and the pattern of presumptive reasoning is shown to be the cornerstone of kairos and the fallacy of straw man. By taking a proposition for granted, the speaker shifts the burden of proving its un-acceptability onto the hearer. The resemblance of the tacit premise (...) with what is commonly acceptable or has been actually stated can be used as a rhetorical strategy. (shrink)

In many actual arguments, the conclusion seems intuitively to follow from the premisses, even though we cannot show that it follows logically. The traditional approach to evaluating such arguments is to suppose that they have an unstated premiss whose explicit addition will produce an argument where the conclusion does follow logically. But there are good reasons for doubting that people so frequently leave the premisses of their arguments unstated. The inclination to suppose that they do stems from the belief that (...) the only way in which an argument's conclusion can follow definitely from its premisses is to follow logically. I argue that this belief is mistaken. I propose a revision of the current generic conception of logical consequence, and its variant specifications, to avoid the paradoxes of strict implication. The revised conception can then be naturally extended to include also what we might call 'enthymematic consequence'. This concept is a kind of consequence, whose properties merit investigation. (shrink)

Any enthymeme can be made logically valid by adding as a suppressed premise a conditional that reiterates the argument's stated content and inferential structure in if-then form, We cannot blanketly prohibit reiteration to avoid this sort of trivialization, because some enthymemes legitimately require completion by reiterative conditionals, The solution proposed here is to allow reiterative expansions, but to rank them, other things being equal, as less charitable than nonreiterative expansions. Reiterative expansions can then be chosen as the most charitable (...) only when all nonreiterative expansions have been eliminated for independent reasons. This pluralistic model encourages experimentation with a number of different permissible expansions in evaluating enthymemes, from the least controversial or problematic to the most trivializing and the least charitable. (shrink)

Bad jokes are not simply non-humorous texts. They are texts that are humorous for someone––their author at least––but not for their audience. Bad jokes thus involve a contextual––pragmatic––dimension that is neglected in the semantic theories of humor. In this paper, we propose an approach to humor based on the Aristotelian notion of surprising enthymemes. Jokes are analyzed as kinds of arguments, whose tacit dimension can be retrieved and justified by considering the “logic” on which it is based. However, jokes (...) are based on specific pragmatic conditions: they are regarded as arguments grounded on a generalization that is at the same time uncommon, retrievable, and acceptable or plausible for the audience. This perspective integrates the “local logic” of jokes within a broader rhetorical theory that ultimately rests on the communicative notion of common ground. (shrink)

Students of geometry do not prove Euclid's first theorem by examining an accompanying diagram, or by visualizing the construction of a figure. The original proof of Euclid's first theorem is incomplete, and this gap in logic is undetected by visual imagination. While cognition involves truth values, vision does not: the notions of inference and proof are foreign to vision.

Journal of Applied Logic, to appear [uncorrected version posted].

In lieu of an abstract, here is a brief excerpt of the content:Philosophy and Rhetoric 37.1 (2004) 21-41 [Access article in PDF] Conquering Our Imagination: Thought Experiments and Enthymemes in Scientific Argument Nathan Crick Department of Communication University of Pittsburgh The dividing line between rhetoric and science has traditionally been drawn at the split between persuasion and logic. On the one side, rhetoric seeks to influence human beliefs and behavior through use of stylistic language that resonates with the experiences (...) of an audience; on the other, science endeavors to describe empirical phenomena through the use of logical propositions that can be understood wholly on their own terms. However, recent scholarship has blurred this border. For instance, in his research on Charles Darwin's rhetorical accomplishments, John Angus Campbell has sought to break down "the neopositivist Berlin Wall separating the context of discovery from the context of justification" that represents this traditional division (1990, 23). Claiming that scientific discovery and rhetorical invention are each "an aspect of a flexible logic of inquiry and presentation" (23), Campbell argues that "the social and theological ring of Darwin's language is not merely decorative or ameliorative, but is constitutive of the fabric of his thought" (5). In other words, Campbell insists there is something intrinsically valuable about Darwin's frequent use of colloquial language beyond its immediate rhetorical appeal—it also contributes something fundamental to scientific knowledge itself.This "something," according to Campbell, is the necessary connection between argument and audience that inspires scientific theorizing and culminates in the establishment of new scientific paradigms. Within the context of discovery, the potential rhetorical audience works as a motivating force in the invention of persuasive arguments. That is why, when Darwin's notebooks are closely examined, it can "be said that virtually every note Darwin penned... was written with an eye to a public, often in response to a nameable individual" (1990, 23). Then, within the context of justification, the actual rhetorical audience works to literally fill in the necessary gaps in any rhetorical argument. That is why Darwin, in order to [End Page 21] tap into this resource, "embedded his central insight in a preexisting common world of thought and feeling" (4). Finally, it is for both of these reasons that one cannot fully reconstruct Darwin's "core concept of his argument as a logical proposition shorn of its colloquial language and associations" (4). For Campbell, "the danger in setting aside Darwin's language is that we effectively remove half of the problem he addressed and disregard the intelligence required to address it—how to present a radical idea to a particular scientific and popular audience in a way that retains the persuasive force of the very tradition it destroys" (5).Campbell's claim that rhetoric is constitutive and cannot be boiled away through logical or reductive analysis asserts the centrality of both stylistic language and audience within the process of scientific argumentation. However, although it is clear that rhetoric has a role to play during revolutionary moments in the history of science, it is not as clear that contemporary audiences cannot go directly to the logical reconstructions of past theories without any significant loss of cognitive value. Thus, we must ask whether a scientific argument, when removed from its immediate persuasive context, can nonetheless be "shorn of its colloquial language and associations" in order to reveal its logical core. What, in other words, is the relationship between the logic of scientific argumentation, the rhetorical appeal of language, and the participation of an audience?This essay suggests that a tentative answer can be found by approaching the question through the concept of the "thoughtexperiment." Thought experiments are distinguished from traditional experiments by their explicitly hypothetical quality. Instead of seeking immediately verifiable empirical results, they are designed to invite an audience to visualize a set of initial conditions and then imagine what might happen in response to those conditions. Galileo, for instance, authored one of the most famous thought experiments when he speculated what would happen if two objects of different weights were tied together and dropped. Einstein tried to envision what we might see from a clear box... (shrink)

To date there seems to be no disciplined way of distinguishing between ad hoc hypotheses and legitimate auxiliary hypotheses. This is embarrassing not just for Popperian falsificationist scientific methodology, for the need for such a distinction seems an important part of scientific practice. Do scientists bother about ad hoc hypotheses at all? Did any towering figure in the history of science care about ad hoc hypotheses? Ironically, the answers to these questions seem to be “Yes” and “No” in both cases. (...) Inspired by Paglieri and Woods’ recent proposal for a theory of enthymeme based on the principle of parsimony, I propose to approach the problem of ad hoc hypothesis by interpreting it as a kind of enthymeme resolution. One reason for this interpretative strategy lies in its potential for understanding the pervasiveness and the longevity of the Aristotelian scientific methodology embedded in the scientific practice throughout the ages. (shrink)

Solves Vann McGee's counterexample to Modus Ponens within classical logic by disclosing the suppressed premises and bringing them /within/ the argument.

What good is logic? -- Seventeen ways this book is different -- The two logics -- All of logic in two pages : an overview -- The three acts of the mind -- I. The first act of the mind : understanding -- Understanding : the thing that distinguishes man from both beast and computer -- Concepts, terms and words -- The problem of universals -- The comprehension and extension of terms -- II. Terms -- Classifying terms -- (...) Categories -- Predicables -- Division -- III. Material fallacies -- Fallacies of language -- Fallacies of diversion -- Fallacies of oversimplification -- Fallacies of argumentation -- Inductive fallacies -- Procedural fallacies -- Metaphysical fallacies -- Short story : love is a fallacy -- IV. Definition -- The nature of definition -- The rules of definition -- The kinds of definition -- The limits of definition -- V. Second act of the mind : judgment -- Judgments, propositions, and sentences -- What is truth? -- The four kinds of categorical propositions -- Logical form -- Euler's circles -- Tricky propositions -- The distribution of terms -- VI. Changing propositions -- Immediate inference -- Conversion -- Obversion -- Contraposition -- VII. Contradiction -- What is contradiction? -- The square of opposition -- Existential import -- Tricky propositions on the square -- Some practical uses of the square of opposition -- VIII. The third act of the mind : reasoning -- What does reason mean? -- The ultimate foundations of the syllogism -- How to detect arguments -- Arguments vs. explanations -- Truth and validity -- IX. Different kinds of arguments -- Three meanings of because -- The four causes -- A classification of arguments -- Simple argument maps -- Deductive and inductive arguments -- Combining deduction and induction : socratic method -- X. Syllogisms -- The structure and strategy of the syllogism -- The skeptics objection to the syllogism -- The empiricist's objection to the syllogism -- Demonstrative syllogisms -- How to construct convincing syllogisms -- XI. Checking syllogisms for validity -- By Euler's circles -- By Aristotle's six rules -- Barbara Celarent : mood and figure -- Venn diagrams -- XII. More difficult syllogisms -- Enthymemes : abbreviated syllogisms -- Sorites : chain syllogisms -- Epicheiremas : multiple syllogisms -- Complex argument maps -- XIII. Compound syllogisms -- Hypothetical syllogisms -- Reductio ad absurdum arguments -- The practical syllogism : arguing about means and ends -- Disjunctive syllogisms -- Conjunctive syllogisms -- Dilemmas -- XIV. Induction -- What is induction? -- Generalization -- Causal induction : Mill's methods -- Scientific hypotheses -- Statistical probability -- Arguments from analogy -- A fortiori and a minore arguments -- XV. Some practical applications of logic -- How to write a logical essay -- How to write a socratic dialogue -- How to have a socratic debate -- How to use socratic method on difficult people -- How to read a book socratically -- XVI. Some philosophical applications of logic -- Logic and theology -- Logic and metaphysics -- Logic and cosmology -- Logic and philosophical anthropology -- Logic and epistemology -- Logic and ethics. (shrink)

In this paper I examine Avicenna’s conception of the consequence relation. I will consider in particular his categorical and hypothetical logics. I will first analyse his definition of the implication and will show that this relation is not a consequence relation in his frame. Unlike the medieval logicians, he does not distinguish explicitly between material and formal consequences. The arguments discussed in al-Qiyās, where the conclusion is true only in some matters, and would seem close to a material consequence for (...) that reason, are rejected explicitly as not syllogistic. He also rejects the ‘enthymemes’ unless they are complemented by their missing premise and the superfluous premises which, according to him, should promptly be ruled out. It seems then that the consequence relation in his theory is formal. It can be characterized as being ‘productivity in all matters’ or ‘necessary truth preserving’. It is illustrated by some single premise arguments, and above all by all kinds of syllogisms which, in his theory, are more numerous and various than in Aristotle’s one. The syllogism may contain two or more premises, including disjunctive ones. When it is hypothetical, it may lead to several conclusions. The premises may be in conflict, but then, the conclusion is false. He thus rejects the principle according to which ‘anything follows from a contradiction’. But, unlike what some scholars say, he does not admit any connexive principle. In the compound syllogisms, the conclusion follows by steps, each step taking two premises at once. (shrink)

Deals with the problem of enthymemes in expert systems designed to model legal reasoning; suggests that interactivity is crucial.

ABSTRACT The logic of humor has been acknowledged as an essential dimension of every joke. However, what is the logic of jokes, exactly? The modern theories of humor maintain that jokes are characterized by their own logic, dubbed “pseudo,” “playful,” or “local,” which has been the object of frequent criticisms. This article intends to address the limitations of the current perspectives on the logic of jokes by proposing a rhetorical approach to humorous texts. Building on the (...) traditional development of Aristotle’s almost neglected view of jokes as surprising enthymemes, the former are analyzed as rhetorical arguments. Like enthymemes, jokes are characterized by natural inferences that can be represented as topics, and quasi-formalized in argumentation theory as argumentation schemes. Like rhetorical arguments, jokes express a reason in support of different types of conclusions and proceed from distinct kinds of reasoning and semantic relations. (shrink)

This paper surveys the various forms of Deduction Theorem for a broad range of relevant logics. The logics range from the basic system B of Routley-Meyer through to the system R of relevant implication, and the forms of Deduction Theorem are characterized by the various formula representations of rules that are either unrestricted or restricted in certain ways. The formula representations cover the iterated form,A 1 .A 2 . ... .A n B, the conjunctive form,A 1&A 2 & ...A n (...) B, the combined conjunctive and iterated form, enthymematic version of these three forms, and the classical implicational form,A 1&A 2& ...A n B. The concept of general enthymeme is introduced and the Deduction Theorem is shown to apply for rules essentially derived using Modus Ponens and Adjunction only, with logics containing either (A B)&(B C) .A C orA B .B C .A C. (shrink)

Lorenzo Valla's rhetorical reform of logic resulted in important changes in sixteenth-century mathematical sciences, and not only in mathematical education and in the use of mathematics in other sciences, but also in mathematical theory itself. Logic came to be identified with dialectic, syllogisms with enthymemes and necessary truth with the limit case of probable truth. Two main ancient authorities mediated between logical and mathematical concerns: Cicero and Proclus. Cicero's 'common notions' were identified with Euclid's axioms, so that mathematics (...) could be viewed as core knowledge shared by all humankind. Proclus' interpretation of Euclid's axioms gave rise to the idea of a universal human natural light of reasoning and of a mathesis universalis as a basic mathematics common to both arithmetic and geometry and as an art of thinking interpretable as algebra. (shrink)

ABSTRACT In this paper, I argue that a number of influential Millian responses to Frege’s puzzle, which consist in denying that Frege’s data apply to natural languages, are not viable if logic is to play its role in legitimizing the logical appraisal of rational subjects. A notion of validity which does justice to the normativity of logic must make room for a distinction between valid inferences and enthymemes. I discuss the prospects of formal, relevant and manifest validity as (...) candidates for a notion which complies with this desideratum. Their success, or failure is argued to hang on the viability of a semantical account of de jure co-reference, which is in tension with standard Millian tenets. I conclude that these Millian theories face the following dilemma: either accept that there is no notion of logical validity which makes logic normative for reasoning, thus jeopardizing our well entrenched practices of rational appraisal; or accept that de jure co-reference is a real semantical relation. (shrink)

This paper suggests that the flaw in the enthymeme approach to argument analysis is in the requirement, as I come to formulate it, that an argument be restated as a premises-and-conclusion sequence. The paper begins by investigating how logicians show that there are problems with the enthymeme approach. That investigation reveals a failure on the part of logicians to appreciate the importance of the rhetorical context of an argument. This failure, it is argued, is a consequence of what (...) I refer to as the Premise-Conclusion Requirement. (shrink)

In the present article I attribute to the common topic in the Rhetoric a two-fold suggestive function and a guarantee function. These three functions are possible because this type of topic, while often quite abstract, nevertheless contains thought-steering, substantial terms, and formulates a generally empirical or normative endoxon. Assuming that according to Aristotle an enthymeme has at least two premises, it would appear that a common topic is the abstract principle behind the often implicit major premise. This means that (...) the topic may be regarded as the – generalizing – if-then statement in a modern argumentation scheme. Therefore it should be possible to see the enthymemes of Rhetoric 2.23 as a combination of a logical argument form (which can usually be reconstructed as modus ponens) and an argumentation scheme – even though we may not attribute this idea to Aristotle himself. (shrink)

Thirteen meanings of 'implication' are described and compared. Among them are relations that have been called: logical implication, material implication,deductive implication, formal implication, enthymemic implication, and factual implication. In a given context, implication is the homogeneous two-place relation expressed by the relation verb 'implies'. For heuristic and expository reasons this article skirts many crucial issues including use-mention, the nature of the entities that imply and are implied, and the processes by which knowledge of these relations are achieved. This paper is (...) better thought of as an early stage of a dialogue than as a definitive treatise. (shrink)

Val Plumwood and Richard Sylvan argued from their joint paper The Semantics of First Degree Entailment and onward that the variable sharing property is but a mere consequence of a good entailment relation, indeed they viewed it as a mere negative test of adequacy of such a relation, the property itself being a rather philosophically barren concept. Such a relation is rather to be analyzed as a sufficiency relation free of any form of premise suppression. Suppression of premises, therefore, gained (...) center stage. Despite this, however, no serious attempt was ever made at analyzing the concept. This paper shows that their suggestions for how to understand it, either as the Anti-Suppression Principle or as the Joint Force Principle, turn out to yield properties strictly weaker than that of variable sharing. A suggestion for how to understand some of their use of the notion of suppression which clearly is not in line with these two mentioned principles is given, and their arguments to the effect that the Anderson and Belnap logics T, E and R are suppressive are shown to be both technically and philosophically wanting. Suppression-freedom, it is argued, cannot do the job Plumwood and Sylvan intended it to do. (shrink)

Contrary to common misconceptions, today's logic is not devoid of existential import: the universalized conditional ∀ x [S→ P] implies its corresponding existentialized conjunction ∃ x [S & P], not in all cases, but in some. We characterize the proexamples by proving the Existential-Import Equivalence: The antecedent S of the universalized conditional alone determines whether the universalized conditional has existential import, i.e. whether it implies its corresponding existentialized conjunction.A predicate is an open formula having only x free. An existential-import (...) predicate Q is one whose existentialization, ∃ x Q, is logically true; otherwise, Q is existential-import-free or simply import-free.How abundant or widespread is existential import? How abundant or widespread are existential-import predicates in themselves or in comparison to import-free predicates? We show that existential-import predicates are quite abundant, and no less so than import-free predicates. Existential.. (shrink)

The evaluation of arguments and argumentation is best understood epistemologically. Epistemic circularity is not formally defective but it may be epistemologically objectionable. Sorenson's doubts about the syntactic approach to circularity are endorsed with qualifications. One explanation of an argument's goodness is its ability to produce justified belief in its conclusion by means of justified belief in its premises, but matters are not so simple for interpersonal argumentation. Even when an argument's premises and conclusion are justified for a speaker, this justifiedness (...) may not be transmissible to every hearer. Still, an epistemic approaeh is instructive. Arguing in enthymemes can be legitimate, e.g., because enthymemes can help produce justified persuasion in an audience that supplies the missing premises. (shrink)

In their book EVALUATING CRITICAL THINKING Stephen Norris and Robert Ennis say: “Although it is tempting to think that certain [unstated] assumptions are logically necessary for an argument or position, they are not. So do not ask for them.” Numerous writers of introductory logic texts as well as various highly visible standardized tests (e.g., the LSAT and GRE) presume that the Norris/Ennis view is wrong; the presumption is that many arguments have (unstated) necessary assumptions and that readers and test (...) takers can reasonably be expected to identify such assumptions. This paper proposes and defends criteria for determining necessary assumptions of arguments. Both theoretical and empirical considerations are brought to bear. (shrink)

An approach to argument macrostructure -- The dialectical nature of argument -- Toulmin's problematic notion of warrant -- The linked-convergent distinction, a first approximation -- Argument structure and disciplinary perspective : the linked-convergent versus multiple-co-ordinatively compound distinctions -- The linked-convergent distinction, refining the criterion -- Argument structure and enthymemes -- From analysis to evaluation.

Acceptance or rejection of factual assertions is a far more important process than logical validation of arguments. Not only are assertions more persuasive than arguments; this is desirable, since we want our beliefs and actions to be reasonable and not just rational. When do we resort to argument? Real speeches heavy on arguments aim to present the speaker as calm, serious, and knowledgeable. In public life, one argues not in order to demonstrate the claim for which one is arguing, but (...) to show that one shares the common prejudices or values that appear in the presuppositions and conclusions of one’s argument, and to demonstrate mastery of the subject matter by displaying relevant knowledge in coherently organized detail. Arguing is thus a way of presenting facts and principles so as to show one’s character as worthy of trust. (shrink)

Most people in countries with the highest climate impact per capita are well aware of the climate crisis and do not deny the science. They worry about climate and have climate engaged attitudes. Still, their greenhouse-gas emissions are often high. How can we understand acting contrary to our knowledge? A simple answer is that we do not want to give up on benefits or compromise our quality of life. However, it is painful to live with discrepancies between knowledge and action. (...) To be able to avoid taking the consequences of our knowledge, we deal with the gap by motivating to ourselves that the action is still acceptable. In this article, we use topical analysis to examine such processes of motivation by looking at the internal deliberation of 399 climate engaged people’s accounts of their reasoning when acting against their own knowledge. We found that these topical processes can be described in at least four different ways which we call rationalization, legitimization, justification and imploration. By focusing on topoi we can make visible how individual forms of reasoning interact with culturally developed values, habits and assumptions in creating enthymemes. We believe that these insights can contribute to understanding the conditions for climate transition communication. (shrink)

Identifying the missing or unstated premisses of arguments is important, because their logical quality depends on them. Textbook authors regard enthymematic syllogisms (e.g., "Elvis is a man, so Elvis is mortal") as having an unstated premiss - the major premiss (e.g., "All men are mortal"). They are said to be such because these syllogisms become formally valid when the major premiss is added (i.e., it is a gap-filler). I argue that unstated major premises are not gap-fillers: they support a part (...) of the argument that is already given implicitly - the inference claim ("If the premisses are true then the conclusion is true"). As such, their logical status is the same as that of an unstated proposition that supports the minor premiss, which is not part of the argument. Therefore, the so-called "major premiss" is not an unstated premiss of the enthymeme. (shrink)

Shouldn't we be convinced by good arguments and not by bad ones? But there are valid arguments with true premises that are not known to be true. What we minimally expect is that people follow the logic of the argument. How will they do this? Descartes advised us to perceive clearly and distinctly the steps in the argument. Aristotle looked toward the enthymeme so that the audience would draw the conclusion on their own. These 'thinking through' strategies are (...) an aid to conviction but cannot guarantee it. Do we need the fallacies and other dirty tricks of rhetoric after all? (shrink)

Peirce's study of Kant, and later of Hegel, and Dewey's (1930) retention of much of Hegel's social philosophy are recognised idealist sources of pragmatism. Here I argue that the transition from idealism to pragmatic realism was already achieved by Hegel. Hegel's ‘Objective Logic’ corresponds in part to Kant's ‘Transcendental Logic’ (WdL,GW21:47.1-3). Hegel faults Kant for relegating concepts of reflection to an Appendix to his Transcendental Logic (WdL,GW12:19.34-38), and for treating reason as ‘only dialectical’ and as ‘merely regulative’ (...) (WdL,GW12:23.12,.16-17). I present three important yet neglected features of Kant'sCritique of Pure Reasonwhich are key enthymemes undergirding Hegel's critical reconstruction of Kant's Critical philosophy (§2). I then summarise some features of the philosophical context within which Hegel begins to re-assess and reconstruct Kant's Transcendental Logic (§3), and review several key steps in this direction Hegel undertook in the 1807Phenomenology(§4). (A related paper extends these results to Hegel'sLogicandEncyclopaedia.) These points show that Hegel's reanalysis of Kant's Critical philosophy is the first and still one of the most sophisticated and adequate pragmatic — specifically pragmatic realist — accounts of thea priori. (shrink)

Among Tolstoy's absolute statements are those that exhibit characteristics of both biblical commands and proverbs—and of other types of absolute statements as well. He also draws, for example, on logical propositions, mathematical deductions, laws of nature and human nature, dictionary definitions, and metaphysical assertions. The language of all these forms is timeless, anonymous, and above all categorical. Their stylistic features imply that they are not falsifiable and that they are not open to qualification: they characteristically include words like "all," "each," (...) "every," "only," and "certainly" and phrases like "there neither is nor can be," "the human mind cannot grasp," and "it is impossible that." Even in sentences that omit such phrases, the very refusal to use a qualifier of any kind can assert unqualifiability. When Tolstoy's absolute statements take the form of syllogisms, the use of the word "therefore" or some explicit or implicit equivalent carries the force of logical inevitability. It carries the same force with Tolstoy's enthymemes, which omit the major premise for the reader to reconstruct. [An example] from The Death of Ivan Ilysch,1 cited above, for instance, contains a minor premise and a conclusion of a syllogism; the reader himself must supply the major premise, which would be: "The simpler and more ordinary a life is, the more terrible it is."· 1. "Ivan Ilysch's life was the most simple and the most ordinary, and therefore the most terrible."Leo Tolstoy, The Death of Ivan Ilysch, ed. John Bayley, trans. Louise and Aylmer Maude , p.225.Gary Saul Morson is an associate professor of Russian literature at the University of Pennsylvania, and the author of The Boundaries of Genre: Dostoevsky's Diary of a Writer and the Traditions of Literary Utopia, and The Broken Frame: The Anti-tradition of Russian Literature. The present article is from a theoretical study of literary creativity and the biography of authors. (shrink)