Even with the lack of consensus on the nature of an argument, the thesis that explanations and arguments are distinct is near orthodoxy in well-known critical thinking texts and in the more advanced argumentation literature. In this paper, I reconstruct two rationales for distinguishing arguments from explanations. According to one, arguments and explanations are essentially different things because they have different structures. According to the other, while some explanations and arguments may have the same structure, they are different things because (...) explanations are used for different purposes than arguments. I argue that both rationales fail to motivate a distinction between arguments and explanations. Since these are the only rationales for distinguishing arguments from explanations that I am prepared to take seriously, I don’t see why we should exclude explanations from being arguments. (shrink)

Identity, existence, predication, necessity, and truth are fundamental philosophical concerns. Colin McGinn treats them both philosophically and logically, aiming for maximum clarity and minimum pointless formalism. He contends that there are real logical properties that challenge naturalistic metaphysical outlooks. These concepts are not definable, though we can say a good deal about how they work. The aim of Logical Properties is to bring philosophy back to philosophical logic.

I advance a pragmatic account of begging the question according to which a use of an argument begs the question just in case it is used as a statement of inference and it fails to state an inference the arguer or an addressee can perform given what they explicitly believe. Accordingly, what begs questions are uses of arguments as statements of inference, and the root cause of begging the question is an argument’s failure to state an inference performable by the (...) reasoners the arguer targets. In these ways, my account is distinguished from other pragmatic accounts. By taking the defect of a question-begging use of an argument to be its failure to state its purported inference, my account highlights in a unique way why question-begging is not an epistemic defect, and why it is not a fallacy, understood as a mistake in reasoning. These points have been made elsewhere, but I believe that their plausibility is enhanced by considering begging the question as nullifying the role of an argument as a statement of inference. Since question-begging uses of arguments fail to state their purported inferences, using an argument in a question-begging-way is not a ratiocinative mistake. This undermines accounts of begging the question that adopt an epistemic approach. (shrink)

I consider the well-known criticism of Quine's characterization of first-order logical truth that it expands the class of logical truths beyond what is sanctioned by the model-theoretic account. Briefly, I argue that at best the criticism is shallow and can be answered with slight alterations in Quine's account. At worse the criticism is defective because, in part, it is based on a misrepresentation of Quine. This serves not only to clarify Quine's position, but also to crystallize what is and what (...) is not at issue in choosing the model-theoretic account of first-order logical truth over one in terms of substitutions. I conclude by highlighting the need for justifying the belief that the definition of first-order logical truth in terms of models is superior to its definition in terms of substitutions. (shrink)

Introduction -- The concept of logical consequence -- Tarski's characterization of the common concept of logical consequence -- The logical consequence relation has a modal element -- The logical consequence relation is formal -- The logical consequence relation is A priori -- Logical and non-logical terminology -- The meanings of logical terms explained in terms of their semantic properties -- The meanings of logical terms explained in terms of their inferential properties -- Model-theoretic and deductive-theoretic conceptions of logic -- Linguistic (...) preliminaries : the language M -- Syntax of M -- The definition of a well formed formula of M -- Semantics for M -- The sentential connectives are defined -- The notion of satisfaction is introduced and the quantifiers are defined -- Model-theoretic consequence -- Truth in a structure -- Satisfaction revisited -- Formalized definition of truth -- Model-theoretic consequence defined -- The model-theoretic definition and the concept of logical consequence -- Does the model theoretic consequence relation reflect the salient features of the common concept of logical consequence? -- What is a logical constant? -- Deductive consequence -- Deductive system n -- The deductive theoretic definition and the concept of logical consequence -- Tarski's criticism of the deductive theoretic definition -- Is N a correct deductive system? (shrink)

I expose a tension in Bertrand Russell's, _Introduction to Mathematical Philosophy, between his account of logical truth and his view that logical truth is knowable without taking into account what the world is like. Russell makes the logical truth of a sentence turn on the actual truth of its second-order universal closure. But this results in making logical truth relative to the number of worldly individuals. I aim to use the tension in _Introduction to Mathematical Philosophy to classify the status (...) of the model-theoretic account as an analysis of the modal notions in classical logic. (shrink)

This paper responds to criticism of the Kripkean account of logical truth in first-order modal logic. The criticism, largely ignored in the literature, claims that when the box and diamond are interpreted as the logical modality operators, the Kripkean account is extensionally incorrect because it fails to reflect the fact that all sentences stating truths about what is logically possible are themselves logically necessary. I defend the Kripkean account by arguing that some true sentences about logical possibility are not logically (...) necessary. (shrink)

This paper distinguishes between two types of persuasive force arguments can have in terms of two different connections between arguments and inferences. First, borrowing from Pinto, an arguer's invitation to inference directly persuades an addressee if the addressee performs an inference that the arguer invites. This raises the question of how invited inferences are determined by an invitation to inference. Second, borrowing from Sorenson, an arguer's invitation to inference indirectly persuades an addressee if the addressee performs an inference guided by (...) the argument even though it is uninvited. This raises the question of how an invitation to inference can guide inferences that the arguer does not use the argument to invite. Focusing on belief-inducing inference, the primary aims here are to clarify what is necessary for an addressee's belief-inducing inference to be invited by an argument used as an instrument of persuasion; and to highlight the capacity of arguments to guide such inferences. The paper moves beyond Pinto's discussion by using Boghossian's Taking Condition in service of and in way that illustrates how epistemically bad arguments can rationally persuade addressees of their conclusions. (shrink)

An account of validity that makes what is invalid conditional on how many individuals there are is what I call a conditional account of validity. Here I defend conditional accounts against a criticism derived from Etchemendy’s well-known criticism of the model-theoretic analysis of validity. The criticism is essentially that knowledge of the size of the universe is non-logical and so by making knowledge of the extension of validity depend on knowledge of how many individuals there are, conditional accounts fail to (...) reflect that the former knowledge is basic, i.e., independent of knowledge derived from other sciences. Appealing to Russell’s pre-Principia logic, I defend conditional accounts against this criticism by sketching a rationale for thinking that there are infinitely many logical objects. (shrink)

Yuval Steinitz has argued that, since it is logically possible that there are logically necessary beings, it follows that there is at least one logically necessary being. Steinitz switches the Leibnitzean ontological argument's concern from perfect beings to logically necessary beings. My paper has two primary aims. First, I argue that Steinitz's quick treatment is insufficient to establish the validity of his argument. Secondly, I argue that the correct approach to logical necessity must account for those possible situations in which (...) the meanings of some of the terms in our language might have been different; on such an approach, the premise of Steinitz's argument is false. My remarks here are intended to add to the prima facie plausibility of Hume's claim that logic has no existential implications. (shrink)

The general issue addressed in this dissertation is: what do the models of formal model-theoretic semantics represent? In chapter 2, I argue that those of first-order classical logic represent meaning assignments in possible worlds. This motivates an inquiry into what the interpretations of first-order quantified model logic represent, and in Chapter 3 I argue that they represent meaning assignments in possible universes of possible worlds. A possible universe is unpacked as one way model reality might be. The problem arises here (...) as to how we are to understand the distinction between the actual and the possible as it relates to modal reality. ;Along with the development of the main arguments in Chapters 2 and 3, the dissertation assesses the status of semantic accounts or logical properties and relations. Specifically, what does the model-theoretic account of a logically possible situation add to the syntactic account ? ;Proofs of invalidity in terms of the models of formal semantics do not establish that it is possible for the premises to be true and the conclusion false, since a formal model is merely given by a consistent set of sentences. Unless there is some way to generate a non-formal model from a formal one, such proofs do not really go beyond syntactic notions. The dissertation ends by concluding that there is no way to generate a non-formal model from a formal one without relying on logical intuitions that are syntactical. ;Hence efforts to construct a semantic basis for model logic independent of syntactic commitments are misguided. However, in classical logic the independence of the semantic account from the syntactic one is grounded on the intuition that it is metaphysically possible for there to be a denumerably infinite totality of objects. (shrink)

In this paper, I consider the criticism due to Hartry Field, John Pollack, William Hanson and James Hawthorne that the Kripkean requirement that a logical truth in modal logic be true at all possible worlds in _all quantified model structures is unmotivated and misses some logical truths. These authors do not see the basis for making the logical truth of a modal sentence turn on more than the model structure given by one reading of the modal operator(s) which occur in (...) the sentence. The primary goal here is to motivate the Kripkean requirement. (shrink)

An increasing number of parents are electing to use daycare to assist them with their parenting from infancy onward. Strikingly, there is scant discussion of whether or not such a practice is morally permissible. In this paper, I shall discuss three different arguments that I believe are implicitly thought to support the use of daycare. I shall argue that the current widespread use of daycare, particularly with respect to infant children, often involves arbitrarily subjugating the needs of children in favor (...) of the desires of parents, and thus is often morally wrong. Finally, I consider a possible fourth argument; one that I believe stands a better chance of justifying the use of daycare, though in the final analysis I argue that it also fails to justify the current widespread use of daycare. (shrink)