This paper explores an idea of Stoic descent that is largely neglected nowadays, the idea that an argument is valid when the conditional formed by the conjunction of its premises as antecedent and its conclusion as consequent is true. As it will be argued, once some basic features of our naıve understanding of validity are properly spelled out, and a suitable account of conditionals is adopted, the equivalence between valid arguments and true conditionals makes perfect sense. The (...) account of validity outlined here, which displays one coherent way to articulate the Stoic intuition, accords with standard formal treatments of deductive validity and encompasses an independently grounded characterization of inductive validity. (shrink)

In this chapter, we take into account Prawitz’s semantics of valid arguments and proofs. Together with the more recent theory of grounds, these semantics belong to the field of proof-theoretic semantics, and have two main sources of inspiration: on the one hand, some pioneering research by Gentzen; on the other, the fundamental results that Prawitz himself has obtained with reference to some of Gentzen’s theories. Along with other ideas stemming from the related intuitionistic tradition, these two suggestions merge in (...) almost all Prawitz’s semantic investigations. Thus, the next section is dedicated to the introduction of some technical—and arguably indispensable—concepts and results. (shrink)

Corcoran, John. 1974. Aristotelian Syllogisms: Valid arguments or true generalized conditionals?, Mind 83, 278–81. MR0532928 (58 #27178) This tightly-written and self-contained four-page paper must be studied and not just skimmed. It meticulously analyses quotations from Aristotle and Lukasiewicz to establish that Aristotle was using indirect deductions—as required by the natural-deduction interpretation—and not indirect proofs—as required by the axiomatic interpretation. Lukasiewicz was explicit and clear about the subtle fact that Aristotle’s practice could not be construed as correctly performed indirect proof. (...) Lukasiewicz evidence is presented fully; it is irrefutable. But, instead of considering the possibility that Aristotle’s discourses were not intended to express indirect proofs of universalized conditions presupposing axiomatic premises, Lukasiewicz came to the amazing conclusion that Aristotle did not understand indirect proof. This paper builds on the admirable Lukasiewicz scholarship to establish a conclusion diametrically opposed to the one Lukasiewicz asserted. This paper points out that if Aristotle had not been establishing an underlying logic but he was instead axiomatizing a theory of terms, Aristotelians could not claim for Aristotle the title Founder of Logic. People who take Euclid, Peano, and Zermelo to have first axiomatized geometry, arithmetic, and set theory, respectively, do not think that this qualifies them for the titles Founder of Geometry, Founder of Arithmetic, and Founder of Set Theory, respectively. Such people do think that this would qualify the three for the titles Founder of Axiomatic Geometry, Founder of Axiomatic Arithmetic, and Founder of Axiomatic Set Theory, respectively: titles that carry no honors in logic. Being the Founder of Axiomatic Term Theory would likewise carry no honors in the field of logic. CORRECTION: The paper inadvertently implied that Euclid was the first to axiomatize geometry. In order to understand Aristotle’s Analytics as a treatise on demonstration it helps to realize that axiomatized geometry was studied in Plato’s Academy when Aristotle was a student. Euclid was the author of the only ancient axiomatized geometry now available. (shrink)

For more than 50 years, Peter Singer has argued that we are required to donate to aid agencies. While many commentators have rejected one or more of his premises, no one appears to have challenged the argument's validity, and it is often assumed to be valid even by critics. This article demonstrates that Singer's common-sense morality arguments for donating to aid agencies are invalid. It then reconstructs a valid version of the argument consistent with Singer's broader (...) work, but shows that this version carries significant costs. The paper concludes that although we have a moral obligation to help those less fortunate, this does not entail an obligation to donate to aid agencies, nor does failing to do so necessarily constitute wrongdoing, provided the obligation to help is otherwise fulfilled. (shrink)

David Miller claims that every valid deductive argument begs the question. Other philosophers and logicians have made similar claims. I show that the claim is false. Its appeal depends on the existence of logical terminology, particularly concerning what a proposition 'contains' or its 'logical content,' that is best understood as metaphoric and that, given its aptness to mislead, would be better eschewed. I show how the terminology appears to derive from early modern theories of the nature of mind, (...) ideas and reasoning that have since been rejected. (shrink)

In recent decades, a number of authors have relied on the multiple realizability argument to reject methodological individualism. In this article, I argue that this strategy results in serious difficulties and makes it impossible to identify social entities and phenomena.

If “no ought from is,” how can bioethics be empirical? Despite the widespread recognition that we can integrate empirical and normative, Hume's Law is still often claimed to pose logical limitations to empirical bioethics. Is Hume's Law a valid argument against empirical bioethics? I argue that we have reasons to answer no. First, I outline and reject two unverified assumptions: that Hume’ s Law, the fact‐value distinction, and the naturalistic fallacy are roughly the same thing, and that Hume's (...) Law is an undisputed meta‐ethical principle which dictates how to formulate normative statements. I then show how the interpretation of Hume's Law as establishing a logical gulf between facts and morality—rather than as clarifying the logical rules of normative argumentation—is dependent upon a non‐cognitivist interpretation of the Is‐Ought problem. I argue that the version of Hume's Law that stems from ethical non‐cognitivism is what is problematic for empirical bioethics. However, other interpretations are possible. We have two reasons to reject the thesis that Hume's Law is an argument against empirical bioethics. First, conflating meta‐ethics and applied ethics is problematic. Second, a non‐cognitivist interpretation of Hume's Law is likely to constitute an argument not only against empirical bioethics, but against all bioethics that claims to be situated within ethical cognitivism, be it empirical or philosophical. Lastly, I present two meta‐ethical postulates shared by empirical and philosophical bioethics. I call them: (1) the “bridge” postulate and (2) the “ethical cognitivism” postulate. (shrink)

This is an introductory guidebook to the basic principles of how to construct good arguments and how to criticeze bad ones. It is non-technical in its approach and is based on 150 key examples, each discussed and evaluated in clear, illustrative detail. Professor Walton, a leading authority in the field of informal logic, explains how errors, fallacies, and other key failures of argument occur. He shows how correct uses of argument are based on sound strategies for reasoned persuasion (...) and critical responses. Among the many subjects covered are: forms of valid argument, relevance, appeals to emotion, personal attack, uses and abuses of expert opinion, problems in deploying statistics, loading terms, equivocation, arguments from analogy, and techniques of posing, replying to, and criticizing questions. The book will be ideally suited to courses in informal logic and in the introduction to philosophy. It will also prove valuable to studetns of pragmatics, rhetoric, and speech communication. (shrink)

This is an introductory guide to the basic principles of constructing good arguments and criticizing bad ones. It is nontechnical in its approach, and is based on 150 key examples, each discussed and evaluated in clear, illustrative detail. The author explains how errors, fallacies, and other key failures of argument occur. He shows how correct uses of argument are based on sound argument strategies for reasoned persuasion and critical questions for responding. Among the many subjects covered are: (...) techniques of posing, replying to, and criticizing questions, forms of valid argument, relevance, appeals to emotion, personal attack, uses and abuses of expert opinion, problems in deploying statistics, loaded terms, equivocation, and arguments from analogy. (shrink)

According to the Bayesian paradigm in the psychology of reasoning, the norms by which everyday human cognition is best evaluated are probabilistic rather than logical in character. Recently, the Bayesian paradigm has been applied to the domain of argumentation, where the fundamental norms are traditionally assumed to be logical. Here, we present a major generalisation of extant Bayesian approaches to argumentation that (i)utilizes a new class of Bayesian learning methods that are better suited to modelling dynamic and conditional inferences than (...) standard Bayesian conditionalization, (ii) is able to characterise the special value of logically valid argument schemes in uncertain reasoning contexts, (iii) greatly extends the range of inferences and argumentative phenomena that can be adequately described in a Bayesian framework, and (iv) undermines some influential theoretical motivations for dual function models of human cognition. We conclude that the probabilistic norms given by the Bayesian approach to rationality are not necessarily at odds with the norms given by classical logic. Rather, the Bayesian theory of argumentation can be seen as justifying and enriching the argumentative norms of classical logic. (shrink)

The article critically examines the arguments of Raef Zreik regarding the 2023 war in Gaza. It first analyzes the use of the concept of narrative in defending political causes and actions. It shows that due to their subjective nature two opposing narratives can be equally valid as long as they satisfy conditions of internal coherence and fidelity to the facts. It then shows that Zreik’s argument of ‘fragmentation’ is double edged and cannot be used for laying full responsibility (...) on Israel. It then proceeds to criticize the claim that Zionism is a colonialist enterprise and shows that Zionism does not consist of all the basic characteristics of colonialism. Finally, it analyzes the common argument of self-defense as the only justification of starting a war and shows the limitation of such an argument in a theory of war, mainly because in most wars both sides have the right to defend themselves, including the allegedly unjust party. All that remains after showing the weakness of most arguments for this or that side to the conflict is the conclusion that compromise is the only way out of the deadlock, having the virtue of being pragmatic rather principled. (shrink)

[1] Experience is a real concrete phenomenon. The existence of experience entails the existence of a subject of experience. Therefore subjects of experience are concretely real. [2] The existence of a subject of experience in the lived present or living moment of experience, e.g. the period of time in which the grasping of a thought occurs, provably involves the existence of singleness or unity of an unsurpassably strong kind. The singleness or unity in question is a metaphysically real, concrete entity. (...) So if thoughts, or any experiences at all, really do occur or exist – and they do – then there exist entities that are genuine, concrete, metaphysical unities of an unsurpassable sort. [3] There is a metaphysically irreproachable sense in which we may – must – take these unsurpassable metaphysical unities to be themselves subjects of experience, although we may also take them to be thoughts or experiences. If so, there is a sound argument to the conclusion of the 2nd Paralogism. [4] Perhaps and are not in the final analysis distinct. Perhaps Kant is right, in his 1772 letter to Herz, that ‘the thinking or the existence of the thought and the existence of my own self are one and the same’. (shrink)

The authors investigated the ontological argument computationally. The premises and conclusion of the argument are represented in the syntax understood by the automated reasoning engine PROVER9. Using the logic of definite descriptions, the authors developed a valid representation of the argument that required three non-logical premises. PROVER9, however, discovered a simpler valid argument for God's existence from a single non-logical premise. Reducing the argument to one non-logical premise brings the investigation of the soundness (...) of the argument into better focus. Also, the simpler representation of the argument brings out clearly how the ontological argument constitutes an early example of a ?diagonal argument? and, moreover, one used to establish a positive conclusion rather than a paradox. (shrink)

The authors investigated the ontological argument computationally. The premises and conclusion of the argument are represented in the syntax understood by the automated reasoning engine PROVER9. Using the logic of definite descriptions, the authors developed a valid representation of the argument that required three non-logical premises. PROVER9, however, discovered a simpler valid argument for God's existence from a single non-logical premise. Reducing the argument to one non-logical premise brings the investigation of the soundness (...) of the argument into better focus. Also, the simpler representation of the argument brings out clearly how the ontological argument constitutes an early example of a ‘diagonal argument’ and, moreover, one used to establish a positive conclusion rather than a paradox. (shrink)

In this paper I demonstrate that most textbook accounts of the linked/convergent distinction fail to conform to the widespread intuition that all valid arguments ought to be classified as linked arguments. I also show that standard textbook accounts of linkage and convergence cannot provide a satisfactory treatment of fallacies of irrelevance and, due to their general insensitivity to the epistemic context in which arguments are offered, must be supplemented by subjective accounts of linkage and convergence which appeal exclusively to (...) authorial beliefs and intentions. (shrink)

This paper is based on the paper draft that I gave to Alfred Mele regarding his original Zygote Argument during my presentation at a small workshop on manipulation arguments in Budapest back in 2012. After that workshop, Mele changed the conclusion of his original Zygote Argument (OZA) from a positive, explanatory conclusion to a negative, non-explanatory conclusion--and, correspondingly, redefined 'incompatibilism' so that it would no longer refer in his work to the view that determinism precludes (undermines, eliminates, destroys, (...) etc.) free will, but refers narrowly to the perhaps spurious association claim that appears in the conclusion of the revised Zygote Argument (Mele 2013+). Yet, over the last decade, Mele has made no comment in print about the changes he made, the invalidity objection that led to them, nor to the fact that his revised Zygote Argument was originally presented by me as a (non-optimal) reaction to my invalidity objection to his original Zygote Argument. To my knowledge, Mele has only mentioned this 2015 paper once, at it was not in the context of understanding manipulation arguments; it was, rather, in the context of defending his revised, non-explanatory definition of 'incompatibilism' at the opening of Aspects of Agency (p. 6, n. 4). There, Mele singles out *just this 2015 paper* as a place where they'll find what Mele degrades as a type of nonstandard/nontraditional definition of 'incompatibilism' that he rejects. This is notable because Mele provides no empirical evidence that his preferred definition is standard, and most (including Lehrer, who coined the term) reject the negative, non-explanatory, association-based definition that Mele came to endorse in the aftermath of my invalidity objection to OZA. So, if Mele had a genuine concern about philosophers who use the term 'incompatibilism', then Mele could have--and should have--named almost any leading figure in free will for this purpose (since most--including Pereboom, Vihvelin, Haji, etc.) reject the non-explanatory definition that Mele-2013+ now endorses. Yet, for untold reasons, Mele isolated the working definition of 'incompatibilism' used in one paper by one unemployed junior researcher to use as his example--even though Neil Levy had used this same definition in previously published work (eg. Levy 2011). Moreover, if Mele were genuinely interested in helping his readers understand the ambiguity of terms like 'compatibilism' and 'incompatibilism' it is a mystery that he referenced a paper in which nothing of substance hung on the definitions given to these terms -- especially considering that he might have instead pointed them to my OTHER 2015 paper, "A Critique of Vihvelin's Three-Fold Classification" in which the MAIN AIM of the paper is to expose the difficulties facing anyone who wants to define the terms 'compatibilism' and 'incompatibilism' in a way that everyone will accept (including a critique of the negative, non-explanatory "incompossibilist" definition that Mele adopted after my objection to OZA). By all appearances, Mele's main aim in citing specifically THIS paper and none of my other work was to give readers the false impression that my working definition of 'incompatibilism' played some role in my charge that his argument is invalid (which it doesn't, given that the term doesn't appear in either the premises or conclusion of that argument). Mele adds to this unseemly rhetorical campaign in his book *Manipulation Agents* where he mentions an invalidity objection in the intro (p. 84) and then discusses that objection in the final lines of Chapter 5 of the book (p. 120-121). The invalidity objection discussed here is completely pedantic, has never been seriously raised in the primary literature (and was previously addressed in multiple places my multiple philosophers, including me), and has nothing whatever to do with my invalidity objection. In other words, Mele was content to discuss an invalidity objection that no one has ever had to an argument that is clearly valid while completely ignoring the ONLY substantive invalidity objection to his argument in print. This is unfortunate, because it has led to serious confusion --including the patently false description of my invalidity objection to OZA as an objection to the revised version of the Zygote Argument that Mele adopted in *response* my objection (e.g., Capes mistakenly claims "Mickelson (2015) contends that arguments like this [i.e. like the revised Zygote Argument] are invalid. But that’s because she defines “incompatibilism” differently than I’ve defined it here" in his "Manipulation Arguments and Direct Arguments" chapter in the 2023 Wiley-Blackwell Companion to Free Will; I did not say this, and the definition of 'incompatibilism' is irrelevant to my objection). In "The Zygote Argument Is Invalid--Now What?", I simply use the invalidity of the simple 2-premise Zygote Argument as a foil to make a series of more philosophically significant points (e.g. regarding the dialectical structure of the free-will debate, the role of best-explanation reasoning, and to develop the first-ever "master manipulation argument"). Mele has yet to address my reasons for calling attention to the non-trivial invalidity of his OZA or to any of my answers to the "Now What?" question in this paper, even though this question and my proposed answers to this question are the paper's main point. For those interested in a more recent discussion of how the logical and metaphilosophical observations made in this "Now What?" paper have helped to move the free-will debate forward, I suggest looking at the discussions of the "paradigm shift" in the free-will debate that helps to explain why the free-will debate has become mired in stalemates and empty verbal disputes that are found, for example, in my contributions to the Wiley-Blackwell Companion to Free Will (Intro and Chapter 4, 2023) and my paper "Free Will, Self-Creation, and the Paradox of Moral Luck" (2019). (shrink)

Havstad (2022) argues that the argument from inductive risk for the claim that non-epistemic values have a legitimate role to play in the internal stages of science is deductively valid. She also defends its premises and thus soundness. This is, as far as we are aware, the best reconstruction of the argument from inductive risk in the existing literature. However, there is a small flaw in this reconstruction of the argument from inductive risk which appears to (...) render the argument invalid. This flaw is superficial, and a small amendment to it rescues the claim of validity. (shrink)

Why have so many philosophers agonised over the possibility of valid arguments from factual premises to moral conclusions? I suggest that they have done so, because of worries over a sceptical argument that has as one of its premises, `All moral knowledge must be non-inferential, or, if inferential, based on valid arguments or strong inductive arguments from factual premises'. I argue that this premise is false.

Why is gauge symmetry so important in modern physics, given that one must eliminate it when interpreting what the theory represents? In this paper we discuss the sense in which gauge symmetry can be fruitfully applied to constrain the space of possible dynamical models in such a way that forces and charges are appropriately coupled. We review the most well-known application of this kind, known as the 'gauge argument' or 'gauge principle', discuss its difficulties, and then reconstruct the gauge (...) argument as a valid theorem in quantum theory. We then present what we take to be a better and more general gauge argument, based on Noether's second theorem in classical Lagrangian field theory, and argue that this provides a more appropriate framework for understanding how gauge symmetry helps to constrain the dynamics of physical theories. (shrink)

This paper revisits a well-known rebuttal of Peter van Inwagen’s consequence argument. This CS-rebuttal, as I shall call it, focuses on the counterfactual structure of alternative possibilities. It shows that the ability to do otherwise is such that if the agent had exercised it, the distant past and/or the laws of nature would have been different. On the counterfactual scenario, there is, therefore, no need for the agent to exercise an ability to change the past or the laws of (...) nature. I first present van Inwagen’s original version of the consequence argument. After exposing some difficulties with Lewis’ famous version of the CS-rebuttal, I proceed by explaining and defending an older and, in my view, superior version. I subsequently discuss a traditional incompatibilist rejoinder, which insists that the past and the laws of nature are fixed. Although this rejoinder delivers a valid argument against the existence of alternative possibilities, it relies on premises the compatibilist explicitly rejects. The outcome of the debate is therefore properly characterized as a genuine dialectical stalemate between compatibilists and incompatibilists. In the final sections of the paper, I demonstrate that attempts by Fischer, Holliday and Fischer and Pendergraft to move beyond the stalemate in favor of the incompatibilist position all fail. I thereby show that the debate is marred by a misunderstanding of the semantics underlying the backtracking conditionals sometimes associated with the compatibilist position. In view of my arguments, the dialectical stalemate between compatibilists and incompatibilists regarding the counterfactual structure of the ability to do otherwise remains fully intact. (shrink)

I first criticize strawson's account of the transcendental deduction, And then argue that wittgenstein's considerations (in his later work) of the rule-Governed nature of judgment can be used to reconstruct a valid argument for a certain kind of objectivity, Which excludes solipsims. I suggest how kant's talk of synthesis can be reinterpreted in the light of this, As indeed can the doctrine of empirical realism and transcendental idealism.

Despite the bad press, Plato has a valid argument for immortality from three premises: (1) if the natural evil of a thing cannot destroy it, then it is indestructible; (2) the natural evil of the soul is vice; and (3) vice cannot destroy the soul. These premises are contestable, of course, but Plato has some good reasons for advancing them.

The Top-Down Argument for the ability to do otherwise aims at establishing that humans can do otherwise in the sense that is relevant for debates about free will. It consists of two premises: first, we always need to answer the question of whether some phenomenon (such as the ability to do otherwise) exists by consulting our best scientific theories of the domain at issue. Second, our best scientific theories of human action presuppose that humans can do otherwise. This paper (...) argues that this is not enough to establish the conclusion. The Top-Down Argument supports that humans can do otherwise _in some sense_. But it does not show that humans can do otherwise _in the sense that is relevant for debates about free will_. The paper then shows that the apparently best way to make the argument valid does not work. (shrink)

Peter van Inwagen’s original formulation of the Consequence Argument employed an inference rule that was shown to be invalid given van Inwagen’s interpretation of the modal operators in the Consequence Argument. In response, van Inwagen recently suggested a revised interpretation of his modal operators. Following up on a debate between Blum and Schnieder, I analyze van Inwagen’s revised interpretation in terms of explanatory notions and I argue that van Inwagen faces a dilemma: he either has to admit that (...) beta entails fatalism, or he has to admit that a new counterexample invalidates beta. Either way, it seems reasonable to reject beta and to conclude that the Consequence Argument fails. Further, I argue that Widerker’s well-known substitute for rule beta is faced with a similar dilemma and, therefore, is bound to fail as well. I conclude that, if the modal operators are interpreted in terms of explanatory notions, neither van Inwagen’s nor Widerker’s rule of inference turns out to be valid. (shrink)

The Modal Perfection Argument (MPA) for the existence of a Supreme Being is a new ontological argument that is rooted in the insights of Anselm, Leibniz and Gödel. Something is supreme if and only if nothing is possibly greater, and a perfection is a property that it is better to have than not. The premises of MPA are that supremity is a perfection, perfections entail only perfections, and the negation of a perfection is not a perfection. I do (...) three things in this paper. First, I prove that MPA is valid by constructing a formal deduction of it in second order modal logic. Second, I argue that its premises are true. Third, I defend the argument and the logic used against some likely objections. (shrink)

This article contends that the first section of Kant's Groundwork of the Metaphysics of Morals provides a sophisticated and valid argument, and that commentators are therefore mistaken in dismissing this section as flawed. In particular, the article undertakes to show that in this section Kant argues from a conception of the goodness of a good will to two distinctive features of moral goodness, and from these features to his?formula of universal law?. The article reveals the sophistication and validity (...) of this argument by considering it in the light of a number of criticisms that are commonly levelled at the section. In conclusion, the article proposes that this interpretation of the section also has significant implications for the understanding of Kant's method, his formulas and his basic conception of the?moral? (shrink)

I offer a new argument for the principle that there are no true contradictions. Because the argument relies mostly on extra-logical premises and is valid in a wide range of logics (including certain paraconsistent logics), it offers a logic-neutral justification of the law of non-contradiction.

An argument evaluation inventory distinguishing between different levels of theory-evidence differentiation was designed corresponding to the levels of argument observed in argument generation tasks. Five scenarios containing everyday theories about a social problem, and arguments to support those theories were presented to 170 participants from two age groups (15 and 22 years) and different educational tracks. Participants had to rate the validity of arguments proposed by a story figure, to support the theory, to choose the best (...) class='Hi'>argument, and to justify their choice. The rating task proved to be very difficult for all age groups, with only 49% of the university students consistently rating valid evidence-based arguments higher than flawed arguments. Competence improved with age and educational level. In the choice task more than 80% of the adults preferred an argument that reflected theory-evidence differentiation over mere theory elaboration or flawed reasoning. However, only adults with a university education were able to also explicitly justify their choice. Overall, these findings imply that laypersons have similar conceptual problems in differentiating theory from evidence as it has been reported for evidence generation tasks (Kuhn, 1991). Performance on the choice task suggests that some implicit awareness of differences between theory and evidence may precede a full, explicit understanding. Implications for education are discussed. (shrink)

Sober has reconstructed the biological design argument in the framework of likelihoodism, purporting to demonstrate that it is defective for intrinsic reasons. We argue that Sober’s restriction on the introduction of auxiliary hypotheses is too restrictive, as it commits him to rejecting types of everyday reasoning that are clearly valid. Our account shows that the design argument fails, not because it is intrinsically untestable but because it clashes with the empirical evidence and fails to satisfy certain theoretical (...) desiderata (in particular, unification). Likewise, Sober’s critique of the arguments from imperfections and from evil against design is off the mark. (shrink)

Putnam's model theoretic argument against metaphysical realism can be reconstructed as valid, with premises acceptable to the realist. There is no illegitimate assumption that the causal theory of reference is false.

The ontological argument has run for a long time, regularly refuted, regularly re-appearing in a new form. Something can be learnt from its longevity. Its proponents must be on to something, or it would not have survived its many refutations. But equally, it must have been much misformulated, or it would not have seemed evidently fallacious to its many critics. Perhaps it does express a deep philosophical intimation. Certainly it has been taken to prove more than it really can (...) establish. Like many other philosophical arguments it has suffered by being made out to be more rigorous than in the nature of the case it can be. For some philosophers addressing some questions it may have been decisive in leading them to adopt one of the few options open to them: but it is quite inconclusive for others, with different presuppositions or different problems, and cannot be reduced into a valid proof cogent for all comers and compelling them to accept the conclusion it claims to demonstrate. (shrink)

This is a critical examination of Johnstone's thesis that all valid philosophical arguments are ad hominem. I clarify his notions of valid, philosophical, and ad hominem. I illustrate the thesis with his refutation ofthe claim that only ordinary language is correct. r discuss his three supporting arguments (historical, theoretical, and intermediate). And r criticize the thesis with the objections that if an ad hominem argument is valid, it is really ad rem; that it's unclear how his (...) own theoretical argument can be ad hominem; that if an ad hominem argument is really valid, it would have to be based on the proponent's own assumptions; and that the thesis is not true of philosophical arguments that are constructive rather than critical. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Kinship:The Relationship Between Johnstone's Ideas about Philosophical Argument and the Pragma-Dialectical Theory of ArgumentationFrans H. van Eemeren and Peter Houtlosser1. Johnstone on the Nature of Philosophical ArgumentAs he himself declared in Validity and Rhetoric in Philosophical Argument (1978, 1), the late philosopher Henry W. Johnstone Jr. devoted a long period of his professional life to clarifying the nature of philosophical argument. His well-known view was that (...) philosophical arguments are sui generis, i.e., not to be judged by the standards of argumentation in science or everyday discourse. Philosophical arguments are not ad rem, but are based on premises that are expressed or implied commitments of a party in dialogue. This is why philosophical argumentation is, according to Johnstone, always ad hominem. In philosophical argumentation, every ad rem argument begs the question.Usually, ad hominem argumentation is dismissed as invalid. Johnstone, however, maintains that making use of argumentum ad hominem is the only way to establish a philosophical conclusion. In an argumentum ad hominem, inferences are drawn from propositions stated or implied by the other party and critical questions are raised about the conclusions that were drawn, so that it can be used to refute a philosophical position by showing that this position is inconsistent. As Walton (2001) rightly observes, this type of ad hominem argumentation boils down to arguing from commitments of the other party, i.e., ex concessis.The use of ad hominem argumentation as the criticism of a position in terms of its own presuppositions is, in Johnstone's view, the only valid argument in philosophy, if any philosophical argument is indeed valid. All philosophical polemic is in this perspective in fact addressed ad hominem. This applies not only to philosophical argumentation that concerns self-referential refutation but also to other ad hominem types of philosophical argumentation, including the tu quoque argument (1978, 11–12).According to Johnstone, there is no objective criterion for determining the validity of ad hominem argumentation. Validity must, says Johnstone in the [End Page 51] epilogue of his collected essays on philosophical argument, be viewed as "a regulative ideal" (135). Much earlier, Johnstone had already come to the conclusion that "the valid argument is the one that maintains philosophical discussion" (38). It is this self-perpetuating feature that is the distinctive rationality of philosophy. By forcing the interlocutor to elaborate his philosophical position rather than just repeat it, the gap between the interlocutors is bridged.In order to distinguish between constructive persuasive argumentation and mere repetition or other forms of paralyzing the discourse, the line must be drawn between responsible and irresponsible persuasion. This is a problem for Johnstone. Where the Ancients solved the problem by insisting that the persuader be virtuous, Johnstone proposed to base the distinction between responsible and irresponsible persuasion on the attitude of the philosopher and his interest in maintaining the philosophical enterprise. The philosopher is a critic who criticizes con amore. His intention to do so, however, is revealed "only in the way he goes about his work" (84).A more down to earth criterion for responsible persuasion that Johnstone proposed is that the discourse should not tend to degenerate. Logic, as the discipline concerned with reason, serves to prevent the discussion from degenerating, but it can do so only if the parties concerned have jointly committed themselves to certain logical principles. If in philosophical argument a defendant is under no obligation to acknowledge an inconsistency when the other party points out an inconsistency in his position, then the other party's criticism cannot count as valid. According to Johnstone, however, it will depend on the parties' presuppositions whether or not they consider two statements as being inconsistent. In other words, what is inconsistent for the one party may not be inconsistent for the other party.Few obligations are imposed on everyone; most obligations arise from commitments made by specific individuals or groups of individuals. As Johnstone says, "Even the cogent philosophical argument is not, of course, absolutely cogent; it is cogent only relatively to interlocutors who maintain the premises on which it depends" (27). Once we abandon the search for objective conditions under which philosophical arguments can be valid, according... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Kinship:The Relationship Between Johnstone's Ideas about Philosophical Argument and the Pragma-Dialectical Theory of ArgumentationFrans H. van Eemeren and Peter Houtlosser1. Johnstone on the Nature of Philosophical ArgumentAs he himself declared in Validity and Rhetoric in Philosophical Argument (1978, 1), the late philosopher Henry W. Johnstone Jr. devoted a long period of his professional life to clarifying the nature of philosophical argument. His well-known view was that (...) philosophical arguments are sui generis, i.e., not to be judged by the standards of argumentation in science or everyday discourse. Philosophical arguments are not ad rem, but are based on premises that are expressed or implied commitments of a party in dialogue. This is why philosophical argumentation is, according to Johnstone, always ad hominem. In philosophical argumentation, every ad rem argument begs the question.Usually, ad hominem argumentation is dismissed as invalid. Johnstone, however, maintains that making use of argumentum ad hominem is the only way to establish a philosophical conclusion. In an argumentum ad hominem, inferences are drawn from propositions stated or implied by the other party and critical questions are raised about the conclusions that were drawn, so that it can be used to refute a philosophical position by showing that this position is inconsistent. As Walton (2001) rightly observes, this type of ad hominem argumentation boils down to arguing from commitments of the other party, i.e., ex concessis.The use of ad hominem argumentation as the criticism of a position in terms of its own presuppositions is, in Johnstone's view, the only valid argument in philosophy, if any philosophical argument is indeed valid. All philosophical polemic is in this perspective in fact addressed ad hominem. This applies not only to philosophical argumentation that concerns self-referential refutation but also to other ad hominem types of philosophical argumentation, including the tu quoque argument (1978, 11–12).According to Johnstone, there is no objective criterion for determining the validity of ad hominem argumentation. Validity must, says Johnstone in the [End Page 51] epilogue of his collected essays on philosophical argument, be viewed as "a regulative ideal" (135). Much earlier, Johnstone had already come to the conclusion that "the valid argument is the one that maintains philosophical discussion" (38). It is this self-perpetuating feature that is the distinctive rationality of philosophy. By forcing the interlocutor to elaborate his philosophical position rather than just repeat it, the gap between the interlocutors is bridged.In order to distinguish between constructive persuasive argumentation and mere repetition or other forms of paralyzing the discourse, the line must be drawn between responsible and irresponsible persuasion. This is a problem for Johnstone. Where the Ancients solved the problem by insisting that the persuader be virtuous, Johnstone proposed to base the distinction between responsible and irresponsible persuasion on the attitude of the philosopher and his interest in maintaining the philosophical enterprise. The philosopher is a critic who criticizes con amore. His intention to do so, however, is revealed "only in the way he goes about his work" (84).A more down to earth criterion for responsible persuasion that Johnstone proposed is that the discourse should not tend to degenerate. Logic, as the discipline concerned with reason, serves to prevent the discussion from degenerating, but it can do so only if the parties concerned have jointly committed themselves to certain logical principles. If in philosophical argument a defendant is under no obligation to acknowledge an inconsistency when the other party points out an inconsistency in his position, then the other party's criticism cannot count as valid. According to Johnstone, however, it will depend on the parties' presuppositions whether or not they consider two statements as being inconsistent. In other words, what is inconsistent for the one party may not be inconsistent for the other party.Few obligations are imposed on everyone; most obligations arise from commitments made by specific individuals or groups of individuals. As Johnstone says, "Even the cogent philosophical argument is not, of course, absolutely cogent; it is cogent only relatively to interlocutors who maintain the premises on which it depends" (27). Once we abandon the search for objective conditions under which philosophical arguments can be valid, according... (shrink)

Neil Tennant and Joseph Salerno have recently attempted to rigorously formalize Michael Dummett's argument for logical revision. Surprisingly, both conclude that Dummett commits elementary logical errors, and hence fails to offer an argument that is even prima facie valid. After explicating the arguments Salerno and Tennant attribute to Dummett, I show how broader attention to Dummett's writings on the theory of meaning allows one to discern, and formalize, a valid argument for logical revision. Then, after (...) correctly providing a rigorous statement of the argument, I am able to delineate four possible anti-Dummettian responses. Following recent work by Stewart Shapiro and Crispin Wright, I conclude that progress in the anti-realist's dialectic requires greater clarity about the key modal notions used in Dummett's proof. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Kinship:The Relationship Between Johnstone's Ideas about Philosophical Argument and the Pragma-Dialectical Theory of ArgumentationFrans H. van Eemeren and Peter Houtlosser1. Johnstone on the Nature of Philosophical ArgumentAs he himself declared in Validity and Rhetoric in Philosophical Argument (1978, 1), the late philosopher Henry W. Johnstone Jr. devoted a long period of his professional life to clarifying the nature of philosophical argument. His well-known view was that (...) philosophical arguments are sui generis, i.e., not to be judged by the standards of argumentation in science or everyday discourse. Philosophical arguments are not ad rem, but are based on premises that are expressed or implied commitments of a party in dialogue. This is why philosophical argumentation is, according to Johnstone, always ad hominem. In philosophical argumentation, every ad rem argument begs the question.Usually, ad hominem argumentation is dismissed as invalid. Johnstone, however, maintains that making use of argumentum ad hominem is the only way to establish a philosophical conclusion. In an argumentum ad hominem, inferences are drawn from propositions stated or implied by the other party and critical questions are raised about the conclusions that were drawn, so that it can be used to refute a philosophical position by showing that this position is inconsistent. As Walton (2001) rightly observes, this type of ad hominem argumentation boils down to arguing from commitments of the other party, i.e., ex concessis.The use of ad hominem argumentation as the criticism of a position in terms of its own presuppositions is, in Johnstone's view, the only valid argument in philosophy, if any philosophical argument is indeed valid. All philosophical polemic is in this perspective in fact addressed ad hominem. This applies not only to philosophical argumentation that concerns self-referential refutation but also to other ad hominem types of philosophical argumentation, including the tu quoque argument (1978, 11–12).According to Johnstone, there is no objective criterion for determining the validity of ad hominem argumentation. Validity must, says Johnstone in the [End Page 51] epilogue of his collected essays on philosophical argument, be viewed as "a regulative ideal" (135). Much earlier, Johnstone had already come to the conclusion that "the valid argument is the one that maintains philosophical discussion" (38). It is this self-perpetuating feature that is the distinctive rationality of philosophy. By forcing the interlocutor to elaborate his philosophical position rather than just repeat it, the gap between the interlocutors is bridged.In order to distinguish between constructive persuasive argumentation and mere repetition or other forms of paralyzing the discourse, the line must be drawn between responsible and irresponsible persuasion. This is a problem for Johnstone. Where the Ancients solved the problem by insisting that the persuader be virtuous, Johnstone proposed to base the distinction between responsible and irresponsible persuasion on the attitude of the philosopher and his interest in maintaining the philosophical enterprise. The philosopher is a critic who criticizes con amore. His intention to do so, however, is revealed "only in the way he goes about his work" (84).A more down to earth criterion for responsible persuasion that Johnstone proposed is that the discourse should not tend to degenerate. Logic, as the discipline concerned with reason, serves to prevent the discussion from degenerating, but it can do so only if the parties concerned have jointly committed themselves to certain logical principles. If in philosophical argument a defendant is under no obligation to acknowledge an inconsistency when the other party points out an inconsistency in his position, then the other party's criticism cannot count as valid. According to Johnstone, however, it will depend on the parties' presuppositions whether or not they consider two statements as being inconsistent. In other words, what is inconsistent for the one party may not be inconsistent for the other party.Few obligations are imposed on everyone; most obligations arise from commitments made by specific individuals or groups of individuals. As Johnstone says, "Even the cogent philosophical argument is not, of course, absolutely cogent; it is cogent only relatively to interlocutors who maintain the premises on which it depends" (27). Once we abandon the search for objective conditions under which philosophical arguments can be valid, according... (shrink)

Desmond Clarke's remarks on “my” absurdity argument are puzzling. i) Although I do indeed still believe it to be a valid argument, I certainly would not claim credit for it. I believe that “Reducibility: Another Side Issue?” put the general problem of the reducibility of mind into a somewhat unorthodox context, but the particular claim Clarke is attacking forms only one very unoriginal step in the general argument of that essay. ii) Some points that Clarke makes (...) I would certainly agree to, and believe I have agreed to in some of the texts he cites, while others are far from anything I meant to convey. Under Clarke's, 1) of course the “antinomies” of the paper above referred to trade on ambiguities. That's one of the points of the paper. 2) in both “Reducibility … ” and “To Have A Mind …”, I have tried to specify the sense in which “mechanism” was being used. That I do not take such terms as self-explanatory should be clear, for instance, from the remarks in the latter paper that immediately follow the passage Clarke criticizes. 3) I have no idea how physics is to develop in the future, nor did I wish to suggest that I did. With the rest of Clarke's I entirely agree. As to his, I fail to see its relevance to my argument, unless it simply leads up to and, with which, again, I wholeheartedly concur. Nancy Maull's paper, which Clarke refers to, for example, seems to me to shed great light on what used to be thought the problem of reduction; I don't see how her argument conflicts with “mine.” iii) Clarke's two “interpretations” of “my” argument are even more puzzling. The first paragraph is clear, as far as it goes. But the second is entirely murky. Perhaps I may try to reconstruct it. “The question for the scientist of a reductivist disposition in this context,” Clarke writes, “is: would it be possible to construct an alternative theory which adequately explains the same phenomena as the human sciences?” Fair enough. But apparently one is not allowed to reflect about an answer to this question. One has to wait and see if such a theory does develop. And meantime to notice that any theory by its very nature is intentional: this is to use some part of the human sciences to establish the explanatory power of all the human sciences. Is that what is meant? If so, I would reply: that the claim that theories are inherently intentional is not a thesis of any “human science” but a philosophical thesis about the nature of intelligible discourse. If a wholly non-intentional theory of human action were stated it would invalidate itself as theory. Thus, to respond to the major accusation of, we would have an answer to Clarke's question such that the question could not have been asked. What we have, then, is not a petitio but a valid reductio ad absurdum. (shrink)

Samuel Rickless presents a new account of Berkeley's controversial argument, and suggests it is the philosopher's greatest legacy: not only is it valid, but it may well be sound.

This essay contends that Spinoza’s argument for the conatus doctrine does not commit any of the five fallacies of equivocation. The key to a better understanding of his argument lies in a Spinoza’s “theory of inherence” — that is, his theory of what it is to be “in” something. Spinoza’s conatus argument is a valid demonstration from Spinozistic premises about inherence, conception, causation, and related matters. These premises reflect his deep commitment to a rigorous Principle of (...) Sufficient Reason, to a conception of things as causing their own properties through their essences, and to a closely-related conception of causation as identical with or parallel to logical consequence. (shrink)

SummaryIn the ‘Second Analogy’, Kant provides a deductive argument as proof that ‘Every event has a cause’. This claim, GLC is the conclusion of a valid argument consisting of five premises P1... P5, which jointly imply GLC. The premises P1... P5 are true, empirical statements about successive perceptual sequences when they serve as ground for correctly saying s1 ‘This is an event’, or s2 ‘This is a new happening’, or s3 ‘I perceive an objective successive sequence of (...) percepts’.However, unlike these premises or even s type statements, Kant's conclusion, GLC, is not a statement that is asserted within empirical or experiential discourse. No one can say on purely observational grounds that every event has a cause since no one can be a witness to every event for all time. But as an unstated claim whose truth is a necessary condition for the truth of P1... P5 (p1... p5 jointly imply GLC), GLC is a presupposition. Furthermore, GLC is true without doubt since the premises that presuppose it are obviously true under the present minimal interpretation. Thus, while GLC is not established by observation of constant uniformities, as Hume correctly believed, neither, is its truth merely presupposed by Kant, who deductively demonstrated the truth of this important presupposition in answer to Hume. (shrink)

The subtraction argument aims to show that there is an empty world, in the sense of a possible world with no concrete objects. The argument has been endorsed by several philosophers. I show that there are currently two versions of the argument around, and that only one of them is valid. I then sketch the main problem for the valid version of the argument.

In a recent paper, Kristin Mickelson argues that Alfred Mele’s Zygote Argument, a popular argument for the claim that the truth of determinism would preclude free action or moral responsibility, is not valid. This sort of objection is meant to generalize to various manipulation arguments. According to Mickelson, the only way to make such arguments valid is to supplement them with an argument that is an inference to the best explanation. In this paper, I argue (...) that there are two other ways in which the proponent of such manipulation arguments can modify their argument, neither of which requires an inference to the best explanation. I then briefly consider and respond to a worry with one of these proposed solutions. (shrink)

In The Myth of Morality Richard Joyce presents a simple and very influential argument for the truth of moral error theory. In this paper I point out that the argument does not have the form Joyce attributes to it, the argument is not valid in an extensional propositional logic and on the most natural way of explicating the meanings of the involved terms, it remains invalid. I conclude that more explanation is needed if we are to (...) accept this particular argument for moral error theory. (shrink)

In the writings of Henry W. Johnstone, Jr. there can be found an evolving and gradually more sophisticated discussion of the relationship between rhetorical and dialectical argument. Johnstone's view on these matters was highly original, and at odds with the prevailing logical empiricism of the time, much like Toulmin's views on argumentation in The Uses of Argument (1958). In view of the rising importance of the issue of the relationship between rhetoric and informal logic, Johnstone's analysis of the (...) argumentum ad hominem, and its relationship to Hamblin's notion of commitment, is especially worth careful consideration. (shrink)

:According to an influential argument in business ethics and economics, firms are normatively required to maximize their contributions to social welfare, and the way to do this is to maximize their profits. Against Michael Jensen's version of the argument, I argue that even if firms are required to maximize their social welfare contributions, they are not necessarily required to maximize their profits. I also consider and reply to Waheed Hussain's ‘personal sphere’ critique of Jensen. My distinct challenge to (...) Jensen seems to me fatal to any view according to which firms are normatively required to maximize their profits. (shrink)