The Definition of Logical Validity (Hardcover)

Volker Halbach

ISBN 10: 019894554X / ISBN 13: 9780198945543

Published by Oxford University Press, Oxford, 2025

About this Item

Hardcover. According to the semantic definition of logical consequence or validity, an argument is logically valid if, and only if, the conclusion is true under all interpretations under which also all premisses are true. The semantic definition is only a general pattern, and Volker Halbach presents a specific way of spelling out this definition. In contrast to the predominant approaches, truth is taken to be a primitive notion, which is not reduced away by a mathematicaldefinition. An interpretation of a sentence is obtained by replacing non-logical terms uniformly with arbitrary other terms of the same grammatical kind. This conception of interpretations is in line withnaive and straightforward understandings of interpretations that hark back at least to the middle ages. The resulting definition of logical validity combines two advantages: first, it is universal in the sense that it applies not only to a restricted language, but to the entire in which the definition is stated. This is in contrast to definitions of logical validity in higher-order languages. Secondly, it admits the intended interpretation, that is, the interpretationof sentences at their face value without any re-interpretation. Thus, logical consequence is trivial preserving truth. The usual model-theoretic definition lacks this property, although it has always takento be fundamental to logical consequence and warrants its usefulness in philosophy. What does it mean for a conclusion to follow logically from other sentences? Logical consequence is at the basis of any rational reasoning. Textbooks generally give a precise and formal account of logical consequence, but rarely provide a justification for this account. In this monograph the foundations of logical consequence are examined. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.

Seller Inventory # 9780198945543

Bibliographic Details

• Title: The Definition of Logical Validity (Hardcover)
• Publisher: Oxford University Press, Oxford
• Publication Date: 2025
• Language: English
• ISBN 10: 019894554X
• ISBN 13: 9780198945543
• Binding: Hardcover
• Condition: new

About this title

Synopsis

According to the semantic definition of logical consequence or validity, an argument is logically valid if, and only if, the conclusion is true under all interpretations under which also all premisses are true. The semantic definition is only a general pattern, and Volker Halbach presents a specific way of spelling out this definition. In contrast to the predominant approaches, truth is taken to be a primitive notion, which is not reduced away by a mathematical definition. An interpretation of a sentence is obtained by replacing non-logical terms uniformly with arbitrary other terms of the same grammatical kind. This conception of interpretations is in line with naïve and straightforward understandings of interpretations that hark back at least to the middle ages.

The resulting definition of logical validity combines two advantages: first, it is universal in the sense that it applies not only to a restricted language, but to the entire in which the definition is stated. This is in contrast to definitions of logical validity in higher-order languages. Secondly, it admits the intended interpretation, that is, the interpretation of sentences at their face value without any re-interpretation. Thus, logical consequence is trivial preserving truth. The usual model-theoretic definition lacks this property, although it has always taken to be fundamental to logical consequence and warrants its usefulness in philosophy.

About the Author

Volker Halbach, Professor of Philosophy and Fellow of New College, University of Oxford

Volker Halbach is Professor of Philosophy at the University of Oxford and a Fellow of New College. Before coming to Oxford in 2004, he held a position at the University of Constance. He has published numerous books and articles mainly in logic and the philosophy of logic, including The Logic Manual, which has been adopted as introductory textbook at many universities across the world.