Evaluating Arguments Based on Toulmin’s Scheme

Toulmin’s scheme for the layout of arguments (1958, The Uses of Argument, Cambridge University Press, Cambridge) represents an influential tool for the analysis of arguments. The scheme enriches the traditional premises-conclusion model of arguments by distinguishing additional elements, like warrant, backing and rebuttal. The present paper contains a formal elaboration of Toulmin’s scheme, and extends it with a treatment of the formal evaluation of Toulmin-style arguments, which Toulmin did not discuss at all. Arguments are evaluated in terms of a so-called dialectical interpretation of their assumptions. In such an interpretation, an argument’s assumptions can be evaluated as defeated, e.g., when there is a defeating reason against the assumption. The present work builds on recent research on defeasible argumentation (cf. e.g. the work of Pollock, Reiter, Loui, Vreeswijk, Prakken, Hage and Dung). More specifically, the author’s work on the dialectical logic DEFLOG and the argumentation tool ARGUMED serve as starting points.     

On the Special Logic Thesis in Chinese Philosophy

I address the problem of whether philosophy can be international by its claim to represent rationality, hence universality. I argue in favor of this claim by focusing on the special logic thesis in Chinese philosophy. This thesis holds that a different type of logic must be used when studying the Chinese texts. I argue at length against the special logic thesis by examining the problem of human nature in the Confucian philosophers Mencius, Hsün Tzu and Kao Tzu. I show how their arguments can be reconstructed as inductive analogical arguments and as deductive argument. I then broaden the notion of the logic of argumentation into a discussion of metaphysical anti-essentialism and underdetermination in order to resolve the problem of human nature and also to show how the same types of logical analysis (more generally construed) can be applied to the arguments from these Confucian philosophers. Under my treatment, Kao Tzu, somewhat surprisingly, turns out to provide the most insight.     

Wittgenstein,Theories of Meaning,and Linguistic Disjunctivism

This paper argues that Wittgenstein opposed theories of meaning, and did so for good reasons. Theories of meaning, in the sense discussed here, are attempts to explain what makes it the case that certain sounds, shapes, or movements are meaningful linguistic expressions. It is widely believed that Wittgenstein made fundamental contributions to this explanatory project. I argue, by contrast, that in both his early and later works, Wittgenstein endorsed a disjunctivist conception of language which rejects the assumption underlying the question that such theories seek to answer—namely, the assumption that the notion of a meaningful linguistic expression admits of non‐circular analysis. Moreover, I give two arguments in favor of the view I ascribe to Wittgenstein: one based on later Wittgenstein's discussion of meaning skepticism and one based on considerations concerning the identity of linguistic expressions.     

Syntactic features and synonymy relations: a unified treatment of some proofs of the compactness and interpolation theorems

This paper introduces the notion of syntactic feature to provide a unified treatment of earlier model theoretic proofs of both the compactness and interpolation theorems for a variety of two valued logics including sentential logic, first order logic, and a family of modal sentential logic includingM,B,S ₄ andS ₅. The compactness papers focused on providing a proof of the consequence formulation which exhibited the appropriate finite subset. A unified presentation of these proofs is given by isolating their essential feature and presenting it as an abstract principle about syntactic features. The interpolation papers focused on exhibiting the interpolant. A unified presentation of these proofs is given by isolating their essential feature and presenting it as a second abstract principle about syntactic features. This second principle reduces the problem of exhibiting the interpolant to that of establishing the existence of a family of syntactic features satisfying certain conditions. The existence of such features is established for a variety of logics (including those mentioned above) by purely combinatorial arguments.Presented byMelvin Fitting     

On the alleged ineffability of death

A number of recent theorists, all proceeding on the assumption that there is no afterlife, argue that the notion of one's own death defies comprehension in ways that have important implications. Some argue this "ineffability" of death precludes a rational decision to die. Dr. Edwin Shneidman maintains that it makes the notion of our own death unintelligible to each of us. In this paper, these arguments are criticized. It is maintained that death is not so inscrutible as these theorists would have us believe.     

Compositionality,Relevance, and Peirce’s Logic of Existential Graphs

Charles S. Peirce’s pragmatist theory of logic teaches us to take the context of utterances as an indispensable logical notion without which there is no meaning. This is not a spat against compositionality per se , since it is possible to posit extra arguments to the meaning function that composes complex meaning. However, that method would be inappropriate for a realistic notion of the meaning of assertions. To accomplish a realistic notion of meaning (as opposed e.g. to algebraic meaning), Sperber and Wilson’s Relevance Theory (RT) may be applied in the spirit of Peirce’s Pragmatic Maxim (PM): the weighing of information depends on (i) the practical consequences of accommodating the chosen piece of information introduced in communication, and (ii) what will ensue in actually using that piece in further cycles of discourse. Peirce’s unpublished papers suggest a relevance-like approach to meaning. Contextual features influenced his logic of Existential Graphs (EG). Arguments are presented pro and con the view in which EGs endorse non-compositionality of meaning.     

The Moral Dilemmas Debate, Deontic Logic, and the Impotence of Argument

In this paper I argue for modesty concerning what theoretical reason can accomplish in the moral dilemmas debate. Specifically, I contend that philosophers' conclusions for or against moral dilemmas are driven less by rational argument and more by how the moral world intuitively appears to them.I support this thesis by first considering an argument against moral dilemmas, the argument from deontic logic, and showing that its persuasive force depends on one's having already accepted its conclusion. I then make a different, and general, case that any argument in the moral dilemmas debate concerning the defeasibility of conflicting obligations can be marginalized by making not-unreasonable adjustments in the conditions for wrongdoing.These two strands of argument are related by the notion of inescapable wrongdoing. It is our standing intuitions about inescapable wrongdoing which make the relevant deontic logical principles plausible or implausible to us. And whether wrongdoing can be inescapable is central to deciding what the conditions for wrongdoing are. My conclusion is that the arguments in the moral dilemmas debate merely implement whatever standing intuition we have concerning inescapable wrongdoing, and that apart from any such intuition the arguments are unpersuasive.     

Quine on intensional entities: Modality and quantification,truth and satisfaction

In this paper, I reconstruct Quine?s arguments against quantified modal logic, from the early 1940?s to the early 1960?s. Quine?s concerns were not technical. Quine was looking for a coherent interpretation of quantified-in English modal sentences. I argue that Quine?s main thesis is that the intended objectual interpretation of the quantifiers is incompatible with any semantic reading of the modal operators, for example as expressing analytic necessity, unless the entities in the domain of quantification are intensions, i.e. definitional entities. The difficulty is that it makes no sense to say of an ordinary object that it bears a property necessarily or contingently when the necessity or contingency in question is analytic. However, starting in 1960, Quine claims that quantified-in modal sentences can be coherently interpreted only as essentialist predications. When we say about an object that it necessarily F?s, we can only coherently mean that it essentially F?s. In the paper, I argue that adequately qualified the thesis is plausible. Two important qualifications are needed. The first is the assumption that satisfaction is an irreducibly predicative notion, making any explication of satisfaction in terms of truth inadequate. The second is the ontological rejection of purely semantic, i.e. merely definitional, entities. With these qualifications in place, Quine?s rejection of the combination of objectual quantifiers and semantic modalities can be upheld. In this way, we vindicate a qualified version of Quine?s conjecture that quantified modal logic is committed to essentialism.     

Traditional Logic,Modern Logic and Natural Language

In a recent paper Johan van Benthem reviews earlier work done by himself and colleagues on ‘natural logic’. His paper makes a number of challenging comments on the relationships between traditional logic, modern logic and natural logic. I respond to his challenge, by drawing what I think are the most significant lines dividing traditional logic from modern. The leading difference is in the way logic is expected to be used for checking arguments. For traditionals the checking is local, i.e. separately for each inference step. Between inference steps, several kinds of paraphrasing are allowed. Today we formalise globally: we choose a symbolisation that works for the entire argument, and thus we eliminate intuitive steps and changes of viewpoint during the argument. Frege and Peano recast the logical rules so as to make this possible. I comment also on the traditional assumption that logical processing takes place at the top syntactic level, and I question Johan’s view that natural logic is ‘natural’.     

What Is an Inconsistent Truth Table?

Do truth tables—the ordinary sort that we use in teaching and explaining basic propositional logic—require an assumption of consistency for their construction? In this essay we show that truth tables can be built in a consistency-independent paraconsistent setting, without any appeal to classical logic. This is evidence for a more general claim—that when we write down the orthodox semantic clauses for a logic, whatever logic we presuppose in the background will be the logic that appears in the foreground. Rather than any one logic being privileged, then, on this count partisans across the logical spectrum are in relatively similar dialectical positions.     

Composition as a Kind of Identity

Composition as identity, as I understand it, is a theory of the composite structure of reality. The theory’s underlying logic is irreducibly plural; its fundamental primitive is a generalized identity relation that takes either plural or singular arguments. Strong versions of the theory that incorporate a generalized version of the indiscernibility of identicals are incompatible with the framework of plural logic, and should be rejected. Weak versions of the theory that are based on the idea that composition is merely analogous to (one-one) identity are too weak to be interesting, lacking in metaphysical consequence. I defend a moderate version according to which composition is a kind of identity, and argue that the difference is metaphysically substantial, not merely terminological. I then consider whether the notion of generalized identity, though fundamental, can be elucidated in modal terms by reverse engineering Hume’s Dictum. Unfortunately, for realists about possible worlds, such as myself, who understand Hume’s Dictum in terms of duplicates, the elucidation never gets off the ground; for modal primitivists, the elucidation may succeed in capturing some general notion of identity, but it’s characterization is too general to target the particular notion of identity, tied to classical mereology, that is the object of my theorizing. In the end, I have little to offer the skeptic who claims not to understand the relevant notion of generalized identity, or not to take it to be compulsory in providing an account of the structure of reality.     

Saving Mach’s View on Atoms

According to a common belief concerning the Mach-Boltzmann debate on atoms, the new experiments performed in microphysics at the turn of the 19th and 20th centuries confirmed Boltzmann’s atomic hypothesis and disproved Mach’s anti-atomic view. This paper intends to show that this belief is partially unjustified. Mach’s view on atoms consists in fact of different kinds of arguments. While the new experiments in microphysics refute indeed his scientific arguments against the atomic hypothesis, his epistemological arguments are unaffected. In this regard, Mach’s epistemological approach remains relevant for today’s discussion on the status of the notion of atom.     

Moral Luck and the Problem of the Innocent Attacker

The purpose of this paper is to explore the relation between the right to self‐defense against an innocent attacker and the notion of moral luck. It argues that those who accept the existence of such a right rely on the assumption that mere agency makes a significant moral difference – which is precisely the assumption that underlies the view held by believers in moral luck. Those who believe in the right to self‐defense against innocent attackers are thus committed to the idea of moral luck much more than they usually acknowledge. The paper also argues that the arguments offered in support of moral luck, in particular the one based on the relation between agency and self‐identity, might help to shed light on the rather puzzling above right.     

Agency and Human Rights

What grounds human rights? How do we determine that something is a human right? James Griffin has persuasively argued that the notion of agency should determine the content of human rights. However, Griffin's agency account faces the question of why agency should be the sole ground for human rights. For example, can Griffin's notion of agency by itself adequately explain such human rights as that against torture? Or, has Griffin offered a plausible explanation as to why one should not broaden the ground for human rights to include other elements of a good life such as freedom from great pain, understanding, deep personal relations, and so on? These concerns have been raised regarding Griffin's agency account, but in his new book, On Human Rights, Griffin has offered new arguments in support of his view that agency is the sole ground for human rights. In this paper, I examine these new arguments, and I argue that Griffin's arguments are ultimately unsuccessful.     

Fallacies of Accident

In this paper I will attempt a unified analysis of the various examples of the fallacy of accident given by Aristotle in the Sophistical Refutations. In many cases the examples underdetermine the fallacy and it is not trivial to identify the fallacy committed. To make this identification we have to find some error common to all the examples and to show that this error would still be committed even if those other fallacies that the examples exemplify were not. Aristotle says that there is only one solution “against the argument” as opposed to “against the man”, and it is this solution the paper attempts to find. It is a characteristic mark of my analysis that some arguments that we might normally be inclined to say are fallacious turn out to be valid and that some arguments that we would normally be inclined to say are valid turn out to be fallacious. This is (in part) because what we call validity in modern logic is not the same as the apodicticity that Aristotelian syllogisms require in order to be used in science. The fallacies of accident, uniquely among the fallacies, are failures of apodicticity rather than failures of, in particular, semantic entailment. This makes sense in a tensed and token-based logic such as Aristotle’s. I conclude that the closest analogue to the fallacy of accident that we can point to is a fallacy in modal logic, viz., the fallacy of necessity.