The purpose of this book is to develop a terminological structure in which private perceptions can be discussed publicly without bringing into existence the usual unnecessary philosophical problems of confused usage of language. chisholm displays an appraisive, quasi-ethical use of language, whereby he claims that a thing has some particular sensible property is to have adequate evidence that it actually does have that property. (staff).

This new work provides an approachable introduction to the complex system that Making It Explicit mapped out.

Provides comprehensive coverage of logical structure as well as the techniques of formal reasoning.

Provides comprehensive coverage of logical structure as well as the techniques of formal reasoning.

This volume contains 12 papers addressed to researchers and advanced students in informal logic and related fields, such as argumentation, formal logic, and communications. Among the issues discussed are attempts to rethink the nature of argument and of inference, the role of dialectical context, and the standards for evaluating inferences, and to shed light on the interfaces between informal logic and argumentation theory, rhetoric, formal logic and cognitive psychology.

A collection of some of Sellars' lectures and articles from 1951 to 1962.

1. I shall attempt in this paper to give a rounded, if schematic, account of the concept of probability. My central concern will be to clarify the sense in which law-like statements (including 'statistical' law-like statements) are made probable by observational data which, in a sense equally demanding analysis, 'accord' with them.

Formal implication is usually represented by symbolization such as ‘ φx ⊃ Ψx,’ which may be read, “for all values of ‘x’, φx implies Ψx.” If the values of the variable ‘x’, in ‘φx’ and ‘Ψx’ be ‘x1’ ‘x2’ ‘x3’, etc., then … ‘φx’ formally implies ‘Ψx’ if and only if, whatever values of ‘x’, ‘xn’, be chosen, ‘φxn’ materially implies ‘Ψxn’ …However, this still leaves it doubtful which of two possible interpretations of expressions having the form ‘ φx ⊃ (...) Ψx’ is to be taken as correct. … It means one thing to say, “Every existent having the property φ … has also the property Ψ,” and it means quite a different thing to say, “Every thinkable thing which should have the property φ must also have the property Ψ.” The second of these holds only when having the properly φ logically entails having the property Ψ; when ‘Ψx’ is deductible from ‘φx’. … The first of them, however, holds not only in such cases … but also in every case where among existent things, one property is universally accompanied by another. (shrink)

The question addressed in this paper is how the degree of justification of a belief is determined. A conclusion may be supported by several different arguments, the arguments typically being defeasible, and there may also be arguments of varying strengths for defeaters for some of the supporting arguments. What is sought is a way of computing the “on sum” degree of justification of a conclusion in terms of the degrees of justification of all relevant premises and the strengths of all (...) relevant reasons. (shrink)

This paper challenges the view that arguments are (by definition, as it were) attempts to persuade or convince an audience to accept (or reject) a point of view by presenting reasons for (or against) that point of view. I maintain, first, that an arguer need not intend any effect beyond that of making it manifest to readers or hearers that there is a reason for doing some particular thing (e.g., for believing a certain proposition, or alternatively for rejecting it), and (...) second that when an arguer is in fact trying to induce an effect above and beyond rendering a reason manifest, the effect intended—the use to which his or her argument is put—need not be that hearers do what the stated reasons are reasons for doing. Where the actual or intended effect of making a reason R for doing X manifest is something other than doing X, I call it an oblique—as opposed to a direct—effect of making that reason manifest. The core of the paper presents an overview or map of the main categories of effect which arguments can have, and the main sub-types within each category, calling attention to the points at which such effects can be indirect or oblique effects. The purpose of that typology is to make it clear (i) how oblique effects can come about and (ii) how important a role they can play in the conduct of argumentation. (shrink)

Some solo verbal reasoning serves the function of arriving at a correct answer to a question from information at the reasoner’s disposal. Such reasoning is good if and only if its grounds are justified and adequate, its warrant is justified, and the reasoner is justified in assuming that no defeaters apply. I distinguish seven sources of justified grounds and state the conditions under which each source is trustworthy. Adequate grounds include all good relevant information practically obtainable by the reasoner. The (...) claim must follow from the grounds in accordance with a justified general warrant. If this warrant is not universal, the reasoner must be justified in assuming that no exception-making circumstances hold in the particular case to which it is applied. (shrink)

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

The great three-volume Principia Mathematica is deservedly the most famous work ever written on the foundations of mathematics. Its aim is to deduce all the fundamental propositions of logic and mathematics from a small number of logical premisses and primitive ideas, and so to prove that mathematics is a development of logic. This abridged text of Volume I contains the material that is most relevant to an introductory study of logic and the philosophy of mathematics (more advanced students will wish (...) to refer to the complete edition). It contains the whole of the preliminary sections (which present the authors' justification of the philosophical standpoint adopted at the outset of their work); the whole of Part 1 (in which the logical properties of propositions, propositional functions, classes and relations are established); section 6 of Part 2 (dealing with unit classes and couples); and Appendices A and B (which give further developments of the argument on the theory of deduction and truth functions). (shrink)

Is truth a condition of premise adequacy? We may distinguish objective and subjective argument correctness. Objective correctness means true premises rendering the conclusion true or probable. Subjective correctness means acceptable pr emises rendering the conclusion acceptable. Acceptability depends on evidence available and so is internalist. Objective and subjective correctness of the premises is ordinarily distinct. For connection adequacy, objective rightness and subjective righ tness coincide. We recognize entailment or rendering probably a priori. Logic is thus internalist. Logic needs an internalist (...) notion of acceptability for premise evaluation to fall within its purview, although it need not deny the objective sens e of rightness. (shrink)