Carneades is an open source argument mapping application and a programming library for building argumentation support tools. In this paper, Carneades’ support for argument reconstruction, evaluation and visualization is illustrated by modeling most of the factual and legal arguments in Popov v Hayashi.

The paper offers a critical analysis of the research program for formalizing informal logic proposed by Douglas Walton and Thomas Gordon. Since their proposal is based on employing the Carneades Argumentation System, this paper aims at answering two questions: what are main benefits of applying CAS as means for formalizing informal logic, and what are possible extensions of Walton and Gordon’s research program and modifications in employing CAS?

We present a formal, mathematical model of argument structure and evaluation, taking seriously the procedural and dialogical aspects of argumentation. The model applies proof standards to determine the acceptability of statements on an issue-by-issue basis. The model uses different types of premises (ordinary premises, assumptions and exceptions) and information about the dialectical status of statements (stated, questioned, accepted or rejected) to allow the burden of proof to be allocated to the proponent or the respondent, as appropriate, for each premise separately. (...) Our approach allows the burden of proof for a premise to be assigned to a different party than the one who has the burden of proving the conclusion of the argument, and also to change the burden of proof or applicable proof standard as the dialogue progresses from stage to stage. Useful for modeling legal dialogues, the burden of production and burden of persuasion can be handled separately, with a different responsible party and applicable proof standard for each. Carneades enables critical questions of argumentation schemes to be modeled as additional premises, using premise types to capture the varying effect on the burden of proof of different kinds of questions. (shrink)

In this paper, I argue that Carneades' pithanon should be understood as what is probably, though not certainly, true. In this, I oppose, e.g., Burnyeat and Frede, who argue that the pithanon should be understood as the persuasive, and not tied to notions of evidential support. There is a free pdf of this paper available on the OSAP website; see the link below.

Argument invention is a method that can be used to help an arguer find arguments that could be used to prove a claim he needs to defend. The aim of this paper is to show how argumentation systems recently developed in artificial intelligence can be applied to the task of argument invention. One such system called Carneades is featured. Carneades can be used to analyze arguments, evaluate arguments, to make an argument diagram, and to construct arguments from a (...) database. Using some simple examples, the paper explains how Carneades works as a system of argument invention. (shrink)

Carneades is a recently proposed formalism for structured argumentation with varying proof standards, inspired by legal reasoning, but more generally applicable. Its distinctive feature is that each statement can be given its own proof standard, which is claimed to allow a more natural account of reasoning under burden of proof than existing formalisms for structured argumentation, in which proof standards are defined globally. In this article, the two formalisms are formally related by translating Carneades into the ASPIC+ framework (...) for structured argumentation. Since ASPIC+ is defined to generate Dung-style abstract argumentation frameworks, this in effect translates Carneades graphs into abstract argumentation frameworks. For this translation, we prove a formal correspondence and show that certain rationality postulates hold. It is furthermore proved that Carneades always induces a unique Dung extension, which is the same in all of Dung's semantics, allowing us to generalise Carneades to cycle-containing structures. (shrink)

Argument invention is a method that can be used to help an arguer find arguments that could be used to prove a claim he needs to defend. The aim of this paper is to show how argumentation systems recently developed in artificial intelligence can be applied to the task of argument invention. One such system called Carneades is featured. Carneades can be used to analyze arguments, evaluate arguments, to make an argument diagram, and to construct arguments from a (...) database. Using some simple examples, the paper explains how Carneades works as a system of argument invention. (shrink)

Vitale plantea un razonamiento en torno a la existencia y naturaleza de los llamados «derechos colectivos». Tomando al antiguo filósofo Carnéades como pretexto y simple inspiración, el autor explora los argumentos tanto a favor como en contra de la existencia de comunidades homogéneas y de los derechos atribuibles a colectivos. Según Vitale, en ninguno de los dos casos la existencia o inexistencia de derechos colectivos obtie-ne un fundamento sólido. En el fondo, el multiculturalismo no logra evitar la contradic-ción que consiste (...) en el hecho de que los derechos particulares reivindicados por cada una de las comunidades terminan por ser totalmente incompatibles con aquellos igualmente particulares reivindicados por las otras comunidades. (shrink)

Carnéades es un escéptico académico y un pragmático que quiere fundamentar la ética no en la idea de Bien o Valor, sino en la noción de bien útil, convincente y conveniente. Una noción basada no tanto en hacer algo grande que merezca la admiración o el elogio de las personas, sino en no hacer mal a nadie y extender el bienestar personal a la mayoría. Para ello creó una norma o guía, una regla de conducta probable o persuasiva que invitaba (...) a actuar sin pretensiones ni orgullo, decidiendo en cada momento lo que parece más probable o persuasivo en cada ocasión para evitar la apraxia en la acción moral. Además, fue el primero en distinguir entre seguir una acción moral con la pauta de la probabilidad, y la imposibilidad de asentir a ella con seguridad de no equivocarnos. (shrink)

The centrepiece of Cicero's De re publica is a discussion of justice. This discussion, which evokes the theme of the Platonic dialogue after which it was named, consists of a set of three speeches. It begins with a speech opposing justice, placed in the mouth of L. Furius Philus and alleged by him to be modelled on the second of a pair of speeches for and against justice delivered in Rome in 155 B.C. by the Greek Academic philosopher Carneades. (...) Philus' speech lays the dialectical foundation for the two subsequent speeches, a defence of justice as the prerequisite for government by C. Laelius, and an explanation of its role in various forms of government by Scipio Aemilianus. (shrink)

Academic skepticism is usually interpreted as a type of discourse without an assertion (a dialectical interpretation). I argue against this interpretation. One can interpret Carneades’ notion of approval as our notion of weak assertion and thereby ascribe to him his own views (a non-dialectical interpretation). In Academica Cicero reports the debate about the status of approval as a kind of assent among Carneades’ followers, especially the views of Clitomachus and Philo of Larissa. According to Clitomachus, approving impressions implies (...) acting on them without taking them as true, while according to Philo of Larissa, approval is taking something as true without certainty. In more modern terms, we can say that Philo refers to the notion of weak assertion, and Clitomachus to non-assertion. Thus Clitomachus’ reading correlates with a dialectical reading, and Philo’s reading correlates with a non-dialectical reading. Philo’s reading leads to the interpretation of Carneades as a quasi-fallibilist. It is difficult to establish the precise position of the historical Carneades because he was hesitant in his oral teaching. Still, there is some basis in Carneades’ theory for interpreting approval as weak assertion (comprising three degrees of persuasiveness involving rational consideration of what seems to be truth). My aim in this essay is thus to argue that a quasi-fallibilist and non-dialectical reading is applicable to the historical Carneades. (shrink)

Although the so-called "pragmatic" test of truth--the idea that the truth of a statement is a function of its predictive value--is usually credited to william james, we possess a version of this truth-test from the third-century b c in the philosophy of carneades of cyrene, the head of the skeptical "middle academy". like james, carneades denied the existence of absolute truth, in the sense of a truth which no further experience could change, offering instead a criterion of probability, (...) the highest form of which is "the probable and tested". (shrink)

Ancient sceptics, unlike their modern counterparts, claim to live their scepticism. Nowadays scepticism, whether epistemological, moral, or of any other variety, is seen as a purely theoretical position, with no direct bearing on the actual living of one’s life; this is because philosophical theories and everyday attitudes are taken to be in some way “insulated” from one another. Serious questions may be raised about the character of this alleged “insulation,” but these are not my present concern; the fact is that (...) no such split between “the philosophical” and “the ordinary” was entertained in the ancient world. It follows that the viability of scepticism as a way of life is a crucial issue for ancient sceptics. It is no accident that one of the most enduring objections to ancient scepticism is to the effect that the sceptical attitude—that is, the posture of universal suspension of judgement—is incompatible with any kind of normal human action; this was known in antiquity as the charge of apraxia, “inaction.” The sceptics for their part, were just as persistent in arguing that suspension of judgement had no such damaging consequences. In as much as the assessment of actual or imaginable types of human life is the province of ethics, I take this debate between ancient sceptics and their detractors to be, in a broad sense, an ethical debate. (shrink)

with Thomas F. Gordon and Henry Prakken. Artificial Intelligence, forthcoming. [Preprint posted.].

Dans cet article j’examine la situation de la Nouvelle Académie dans la classification du scepticisme élaborée par Jules Vuillemin. Celui-ci, dans une étude intitulée « Une morale est-elle compatible avec le scepticisme? », a distingué quatre types de scepticisme : le scepticisme radical, celui de Pyrrhon ; le scepticisme esthète ou raffiné, celui d’Aristippe ; le probabilisme individuel, celui de Carnéade ; et le probabilisme démocratique, celui de Hume. Or cette classification présente de multiples difficultés. Est-il légitime de faire usage (...) à propos de la Nouvelle Académie du concept de « scepticisme » qui la définit beaucoup plus par rapport au néopyrrhonisme d’Enésidème et de Sextus Empiricus que par rapport à ses racines platoniciennes? Comment ignorer le fait que les arguments de Carnéade n’étaient pas formulés propria persona, mais dans un processus dialectique anti-stoïcien? Et que dire de tous les textes qui, notamment sur la question du plaisir, ne correspondent pas à son analyse? Et pour terminer, le fait que Villemin cite pour l’essentiel le témoignage cicéronien, pose le problème des différences sémantiques entre le latin et le grec. (shrink)

Cet article propose une interprétation de la philosophie de la Nouvelle Académie différente de celle qui a été défendue par J. Annas. Il nous semble que la prise en compte de l'ensemble des témoignages concernant cette école suggère une réalité plus complexe que celle que recouvre le concept de scepticisme, au moins dans sa version néopyrrhonienne. Nous croyons qu'Arcésilas et Carnéade n'ont pas délimité un Platon sceptique, mais qu'ils ont accepté à leur manière l'ensemble de l'héritage platonicien. La force de (...) la tradition apparaît donc plus forte dans l'histoire de l'Académie que ne l'admettent généralement les interprètes. The purpose of this article is to give an interpretation of the New Academy's philosophy quite different from the one defended by J. Annas. In our opinion the reading of the whole testimonies relating to this school suggests a greater complexity than what is embraced by the concept of skepticism, at least in its neopyrrhonian version. We believe that Arcesilas and Carneades, instead of confining Plato whithin the limits of skepticism, have accepted - in their own way - the whole Platonician legacy. Thus the burden of tradition seems more important in the history of the Academy than it is generally admitted. (shrink)

In 155 B.C. Athens sent an embassy to Rome to mediate in the matters raised by the Athenian intervention in the city of Oropos. Although the senate not long before has expelled philosphers and rhetors, they decided to entrust negotiations to the academic Carneades, the stoic Diogenes and the peripatetic Critolao. We know nothing of the role played by the latter two, who in the testimonials that we have either do not appear or are merely mentioned in passing, perhaps (...) because only that which is scandalous tends to be remembered o perhaps because they were not fortunate enough to have Cicero notice them. We are also fortunate that Lactantius conserves parts of the Ciceronian text that otherwise would have been lost. The present paper addresses the relations and interrelations among these three levels of readings: the discourses of Carneades in favor of justice and injustice, the recreation of the discourse on injustice that Cicero puts in the mouth of Philo, and the fragments of Lactantius that allows us to complete the prior two discourses. (shrink)

Dans cet article j’examine la situation de la Nouvelle Académie dans la classification du scepticisme élaborée par Jules Vuillemin. Celui-ci, dans une étude intitulée « Une morale est-elle compatible avec le scepticisme? », a distingué quatre types de scepticisme : le scepticisme radical, celui de Pyrrhon ; le scepticisme esthète ou raffiné, celui d’Aristippe ; le probabilisme individuel, celui de Carnéade ; et le probabilisme démocratique, celui de Hume. Or cette classification présente de multiples difficultés. Est-il légitime de faire usage (...) à propos de la Nouvelle Académie du concept de « scepticisme » qui la définit beaucoup plus par rapport au néopyrrhonisme d’Enésidème et de Sextus Empiricus que par rapport à ses racines platoniciennes? Comment ignorer le fait que les arguments de Carnéade n’étaient pas formulés propria persona, mais dans un processus dialectique anti-stoïcien? Et que dire de tous les textes qui, notamment sur la question du plaisir, ne correspondent pas à son analyse? Et pour terminer, le fait que Villemin cite pour l’essentiel le témoignage cicéronien, pose le problème des différences sémantiques entre le latin et le grec. (shrink)

Dans son article de 1985, « Une morale est-elle compatible avec le scepticisme? », Jules Vuillemin brosse un portrait du philosophe néo-académicien Carnéade en sceptique utilitariste. L’article s’attache à analyser cette lecture en confrontant l’interprétation de Jules Vuillemin avec les sources que nous avons de Carnéade. Il montre que malgré l’anachronisme assumé de son approche, cette interprétation permet de faire apparaître la particularité du scepticisme de Carnéade, notamment la nature rationnelle de la règle d’action selon le probable, grâce à une (...) comparaison avec les théories de la décision. (shrink)

An ancient argument attributed to the philosopher Carneades is presented that raises critical questions about the concept of an all-virtuous Divine being. The argument is based on the premises that virtue involves overcoming pains and dangers, and that only a being that can suffer or be destroyed is one for whom there are pains and dangers. The conclusion is that an all-virtuous Divine (perfect) being cannot exist. After presenting this argument, reconstructed from sources in Sextus Empiricus and Cicero, this (...) paper goes on to model it as a deductively valid sequence of reasoning. The paper also discusses whet her the premises are true. Questions about the possibility and value of proving and disproving the existence of God by logical reasoning are raised, as well as ethical questions about how the cardinal ethical virtues should be defined. (shrink)

Dans son article de 1985, « Une morale est-elle compatible avec le scepticisme? », Jules Vuillemin brosse un portrait du philosophe néo-académicien Carnéade en sceptique utilitariste. L’article s’attache à analyser cette lecture en confrontant l’interprétation de Jules Vuillemin avec les sources que nous avons de Carnéade. Il montre que malgré l’anachronisme assumé de son approche, cette interprétation permet de faire apparaître la particularité du scepticisme de Carnéade, notamment la nature rationnelle de la règle d’action selon le probable, grâce à une (...) comparaison avec les théories de la décision. (shrink)

Harald Thorsrud - Cicero on his Academic Predecessors: the Fallibilism of Arcesilaus and Carneades - Journal of the History of Philosophy 40:1 Journal of the History of Philosophy 40.1 1-18 Cicero on his Academic Predecessors: the Fallibilism of Arcesilaus and Carneades Harald Thorsrud IN AN IMPORTANT PAPER, Couissin argued for what has come to be called the dialectical interpretation of Academic skepticism. On this interpretation, Arcesilaus and Carneades practiced the same, purely dialectical method -- they would elicit (...) assent to premises characteristic of their interlocutor's position and then derive unacceptable consequences exclusively on the basis of those premises. This method allowed them to remain uncommitted to the premises as well as the conclusions of their arguments. They would simply draw logical consequences from their opponents' own premises for the sake of refutation. This is in keeping with the current consensus that an ancient skeptic is one who has no beliefs, or at least no beliefs of a problematically dogmatic sort. Consequently, the methods of ancient skeptics, including Academic skeptics, are thought to be strictly negative, seeking only the elimination of belief. So when we come to Cicero's Philonian version of Academic methodology and find that it explicitly includes provisions for the acquisition of fallible beliefs, it is no surprise that commentators who are sympathetic to the dialectical interpretation tend to view.. (shrink)

The best-known fact about the interaction of the Republican Roman poet Gaius Lucilius (c.180–103/102b.c.e.), the inventor of the genre of Roman verse satire, with the doctrine of Scepticism is probably a statement of Cicero: that Clitomachus the Academician dedicated a treatise to the poet (Cic.Luc. 102). Diogenes Laertius makes much of that writer's, Clitomachus’, industry (τὸ φιλόπονον, 4.67), with the comment: ‘to such lengths did his diligence (ἐπιμελείας) go that he composed more than four hundred treatises’. This phraseology surely reminds (...) those interested in Lucilius’ influence on later Latin poetry of Horace's disparaging comment,in hora saepe ducentos, | ut magnum, uersus dictabat(‘as a bravura display, he would often dictate two hundred verses in an hour’,Sat.1.4.9–10); moreover, Horace shortly afterwards calls his predecessorgarrulus atque piger scribendi ferre laborem(‘talkative and too lazy to bear the work of writing’, 1.4.12). Yet, a sceptical view of Horace's critique might have to think of Lucilius as hard-working, like his putative friend the Academic philosopher, Clitomachus. (shrink)

In this paper, a case study is conducted to test the capability of the Carneades Argumentation System to model the argumentation in a case where forensic evidence was collected in an investigation triggered by a conflict among art experts on the attribution of a painting to Leonardo da Vinci. A claim that a portrait of a young woman in a Renaissance dress could be attributed to da Vinci was initially dismissed by art experts. Forensic investigations were carried out, and (...) evidence was collected by art history experts and scientific experts. The expert opinions were initially in conflict, but new evidence shifted the burden of proof onto the side of the skeptics. This paper presents an analysis of the structure of the interlocking argumentation in the case using argument mapping tools to track the accumulation of evidence pro and con. (shrink)

Despite Kant's explicit statement that every murderer must suffer death, there are at least four situations to be found in Kant's work in which the killing of a human being should not lead to the death penalty: when too many murderers are involved; when a mother kills her illegitimate child; when one duellist kills the other; when one person pushes another off a plank in order to save his life. This paper discusses these situation and concentrates on the last situation (...) - Kant's interpretation of the plank of Carneades – with an eye to what they learn us about Kant understanding of the law. Does Kant acknowledge a legal vacuum? In order to come to a conclusion, Kant's 'solution' of the plank is compared with those suggested by other authors, such as Cicero, Pufendorf and Lon Fuller in his famous 'speluncean explorers' case. (shrink)

En este artículo reconstruyo y analizo las respuestas de los escépticos académicos a la objeción de apraxia. Esta objeción afirma que el escepticismo es una doctrina imposible de practicar puesto que sus tesis conducen a la apraxia, esta es, un estado de privación o imposibilidad de acción. Las respuestas a la objeción se dividen en dos clases. La primera prueba que el asentimiento no es una condición necesaria para realizar acciones, por lo que la recomendación escéptica de suspender global y (...) permanentemente el asentimiento no conduciría a la apraxia. La segunda prueba que es posible deliberar y orientar racionalmente nuestras acciones sin impresiones aprehensivas, por lo que la tesis escéptica de que no existen impresiones aprehensivas tampoco conduciría a la apraxia. Tras unas breves consideraciones generales, en la primera parte de este artículo presento las respuestas de Arcesilao y en la segunda parte las repuestas de Carnéades. (shrink)

Plausible (eikotic) reasoning known from ancient Greek (late Academic) skeptical philosophy is shown to be a clear notion that can be analyzed by argumentation methods, and that is important for argumentation studies. It is shown how there is a continuous thread running from the Sophists to the skeptical philosopher Carneades, through remarks of Locke and Bentham on the subject, to recent research in artificial intelligence. Eleven characteristics of plausible reasoning are specified by analyzing key examples of it recognized as (...) important in ancient Greek skeptical philosophy using an artificial intelligence model called the Carneades Argumentation System (CAS). By applying CAS to ancient examples it is shown how plausible reasoning is especially useful for gaining a better understanding of evidential reasoning in law, and argued that it can also be applied to everyday argumentation. Our analysis of the snake and rope example of Carneades is also used to point out some ways CAS needs to be extended if it is to more fully model the views of this ancient philosopher on argumentation. (shrink)

Ancient philosophy knew two main skeptical traditions: the Pyrrhonian and the Academic. In this final paper of the three‐part series devoted to ancient skepticism, I present some of the topics about Academic skepticism which have recently been much debated in the specialist literature. I will be concerned with the outlooks of Arcesilaus, Carneades, and Philo of Larissa.

It can be said that the roots of the studies on the argumentation theory go back to rhetorical and dialectical studies. One of the sub-fields of the argumentation theory is argument schemes, used in everyday language and various fields within certain rules. Today, with the studies in the field of informal logic, argumentation schemes have aslo become an important field to study. The argumentation schemes approach also plays an important role in the study of artificial language at the intersection of (...) the computer science area. In this article, we discussed Douglas Walton’s argumentation schemes approach. Douglas Walton's aim is to determine the natural language arguments used in various fields and make as a list of them and propose a classification for argumentation schemes. Douglas Walton, presents a model for the argumentation schemes. This model also emphasized the structure suitable for use in computer systems. Determination, analysis and evaluation of arguments are important topics for the arguments applying to computer systems. In this article, we discuss one of these systems, Thomas Gordon’s project, the Carneades Argumentation System. The Carneades Argumentation System is a system which can handle Douglas Walton's argumentation schemes. With the Carneades Argumentation System, it is possible to visualize arguments as an argument map. The visualization of an argumentation provides a concrete basis for philosophical discussions. It makes it easy for the user to determine the scheme of the current argument when applying the argument formats to mapping and evaluation systems such as Carneades Argumentation Systems. Determining the argument scheme allows the argument to be handled within a particular model. The aim of this article is to discuss the argumentation schemes which is one of the topics of study at the intersection of philosophical logic and computer sciences in which informal logic studies are developing today. (shrink)

This paper has three dimensions, historical, theoretical and social. The historical dimension is to show how the Ciceronian system of dialectical argumentation served as a precursor to computational models of argumentation schemes such as Araucaria and Carneades. The theoretical dimension is to show concretely how these argumentation schemes reveal the interdependency of rhetoric and logic, and so the interdependency of the normative with the empirical. It does this by identifying points of disagreement in a dialectical format through using argumentation (...) schemes and critical questions. The social dimension is to show how the Ciceronian dialectical viewpoint integrates with the use of computational tools that can be used to support the principle of reason-based deliberation and facilitate deliberative democracy. (shrink)

In this paper, the Carneades argumentation system is extended to represent a procedural view of inquiry in which evidence is marshalled to support or defeat claims to knowledge. The model is a sequence of moves in a collaborative group inquiry in which parties take turns making assertions about what is known or not known, putting forward evidence to support them, and subjecting these moves to criticisms. It is shown how this model of evaluating evidence in an inquiry is based (...) on a defeasible logic using forms of argument that admit exceptions. It is contended that reasoning from absence of knowledge is as important to inquiry as positive reasoning from evidence to knowledge. The philosophical conflict between this view of reasoning about knowledge and the true-belief-plus view is explored by airing objections and replies on both sides. (shrink)

A fairly long (~15,000 word) overview of ancient theories of freedom and determinism. It covers the supposed threat of causal determinism to "free will," i.e., the sort of control we need to have in order to be rightly held responsible for our actions. But it also discusses fatalistic arguments that proceed from the Principle of Bivalence, what responsibility we have for our own characters, and god and fate. Philosophers discussed include Aristotle, Epicurus, the Stoics, Carneades, Alexander of Aphrodisias, and (...) Plotinus. Plato is mentioned in passing a few times in connection with other philosophers. (shrink)