Definition: A practical guide to constructing and evaluating definitions of terms Definition: A practical guide to constructing and evaluating definitions of terms David Hitchcock WINDSOR STUDIES IN ARGUMENTATION 11 WINDSOR, ON Copyright David Hitchcock and Windsor Studies in Argumentation Digital Copies of Definition: A practical guide to constructing and evaluating definitions of terms by David Hitchcock is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted. Manuscript editing by Tamilyn Mulvaney Cover Art by Jonathan Whitehead (https://www.jonathanwhitehead.com/) To Inga, with love Contents viii Preface ix 1. Introduction 1 1.1 Occasions for defining terms 1 1.2 The definition of ‘term’ 2 1.3 Three dimensions of definitions 3 2. Acts of the definer 7 2.1 Reporting 7 2.2 Stipulating 25 2.3 Advocating 52 3. Content of the definition 76 3.1 Choice of words in the defining part of a 76 definition 3.2 Choice of words suitable for the 82 addressees of a definition 3.3 Theoretical constraints on the choice of 84 words in a definition 3.4 Choice of information to convey 86 4. Forms of definition: normal forms 87 4.1 Definitions by synonym 89 4.2 Definitions by antonym 96 4.3 Definitions by extended synonym 99 4.4 Definitions by genus and differentia 102 4.5 Contextual definitions 124 4.6 Range definitions 137 4.7 Extensional definitions 143 5. Forms of definition: other forms 145 5.1 Operational definitions 145 5.2 Giving examples, non-examples and 154 borderline cases 5.3 Ostensive definitions 159 5.4 Use in a sentence 160 6. Strategies and theoretical issues 164 6.1 Strategies for defining terms 164 6.2 Real versus nominal definitions 166 6.3 Traditional rules for definition 171 6.4 Defining terms versus analyzing concepts 179 6.5 Conceptions of a concept 182 7. Summary 186 7.1 Acts of defining 186 7.2 Content of the defining part of a 189 definition 7.3 Forms of definition 190 7.4 Strategies and theoretical issues 196 7.5 Rarely used forms of definition 199 Appendix: more forms 201 A.1 Inductive definitions 201 A.2 Recursive definitions 203 A.3 Role-specifying definitions 206 Glossary 208 References 252 Index 265 Terms defined in examples 271 “The first thing I’d like to point out is how well the book is crafted. The writing is clear, and, best of all, its synoptic coverage of the topic of definitions will be a very welcome addition to the literature. There are some arresting new points made, and I especially appreciated the range of definition examples considered, from the FBI’s Uniform Crime Reporting on murder to the astronomers’ attempts to define ‘planet’.” Frank Fair Department of Psychology and Philosophy, Sam Houston State University, Huntsville, Texas Past editor, Inquiry: Critical Thinking across the Disciplines . “The discussion is excellent for its clarity, detail and comprehensiveness in presenting various types of definitions, the evidence one may give for them, and their criteria of evaluation. I remember one of my professors in graduate school saying that the profession needs an account gathered together in one place of the various types of definition. In Definition: A practical guide to constructing and evaluating definitions of terms we now have that account.” … James B. Freeman Professor of Philosophy, Hunter College of the City University of New York, New York, NY Past president, Association for Informal Logic and Critical Thinking viii Preface This book proposes practical guidelines for constructing and evaluating definitions of terms, i.e. words or phrases of general application. The guidelines extend to adoption of nomenclature. Although these guidelines have a theoretical background, the book is not a scholarly treatise on the theory of definition. Nor is it a textbook; if used as a supplementary textbook to help develop critical thinking skills, it would need exercises. Rather, the book is a practical guide for people who find themselves in their daily lives or their employment producing or evaluating definitions of terms. It can be consulted rather than being read through. The book’s theoretical framework is a distinction, due to Robert H. Ennis (1962, 101-106; 1996, 320-363; 2016; 2019), of three dimensions of definitions: the act of the definer, the content of the definition, and its form. The act of a definer is what the definer does in defining a term; the book distinguishes, following Ennis, three basic acts of defining: reporting, stipulating, and advocating. The content of a definition is in one sense the information that the definition conveys and in another sense the words in its defining part. The form of a definition is the way it is expressed, for example as a definition by genus and differentia. This book was originally to be co-authored with Ennis. I wrote the first draft, Ennis commented, and we went back and forth until we agreed on a complete manuscript. At that point, however, Ennis decided that he could no longer be a co-author, although the project has his approval. Subsequently, in response to a reviewer’s suggestion (for which I am grateful) that I consult additional publications about definition, I revised the manuscript extensively, adding material that Ennis has not seen. I also benefited from careful reading of a later version of the whole manuscript by James B. Freeman and Frank Fair, and I thank them for their helpful suggestions, which I have generally accepted. They are ix x David Hitchcock of course not responsible for any flaws that remain. I would also like to thank Christopher Tindale for his careful proof-reading of the manuscript and Tamilyn Mulvaney for her care and dedication in preparing the manuscript for publication, as well as Jonathan Whitehead for his creative design of the cover (and Leo Groarke and Kathryn Verhulst-Rogers for arranging for him to design it). I hope that the result will be illuminating and useful for its readers. David Hitchcock January 2020 1. Introduction Every day, all over the world, people explain what a term means, make vague terms precise, stipulate usage, adopt terminology, and use definitions to advocate a position on an issue. 1.1 Occasions for defining terms Consider the following examples. A parent answers a child’s request to explain what an unfamiliar word means. An author composes a dictionary entry or starts an encyclopedia entry with a definition of its topic. The composer of a labour force survey drafts a question designed to determine whether a person who is not currently gainfully employed should be labeled ‘unemployed’.1 The drafters of a new edition of the Diagnostic and Statistical Manual of Mental Disorders reach a decision on the name and diagnostic criteria for a mood disorder. Medical researchers discuss how to define a condition so that results of studies by different research groups can be compared. The drafter of a piece of legislation or a regulation or a contract sets out in the document what its key terms mean. The standardization committee of an academic society recommends a standard nomenclature for a newly discovered compound. Authors of scholarly and scientific articles explain what they mean by their key terms. A school superintendent stipulates how ‘segregation’ is to be defined for 1. This essay uses single quotation marks to indicate use of the word or phrase within them to refer to itself (including its meaning as well as its sound or shape). The essay uses double quotation marks when quoting someone else’s words or as “scare quotes” indicating the apparent oddity of the word or phrase within the quotation marks. 1 2 David Hitchcock the purpose of ensuring conformity to a court’s ban on segregated schools. The present essay is meant to be useful as a guide to these activities and to evaluation of their results. It makes a number of distinctions, and provides criteria to be taken into account by people who want to make their definitions and terms clear. It does not address the formulation of definitions that introduce new terms to axiomatized scientific theories or that make precise how an existing term like ‘force’ or ‘compound’ is to be understood in a scientific theory. The essay does not consider proper names or acts of assigning them. In general, explaining what a proper name like ‘Napoleon Bonaparte’ means requires only pointing (literally or metaphorically) to the person or thing named, not a definition.2 Further, assigning a proper name is largely a matter of free choice, for which general guidelines are neither possible nor helpful. 1.2 The definition of ‘term’ The word ‘term’ in this essay means any word or phrase of general application that is short of a full sentence. Individual words like ‘hockey’ or ‘if’ or ‘pellucid’ or ‘grow’ are terms. So are phrases like ‘major bleeding’ or ‘in the vicinity’ or ‘very carefully’ or ‘well disposed’ or ‘proof beyond a reasonable doubt’ or ‘legal system’. Definite descriptions like ‘the tallest woman in the room’ 2. Some authors (e.g. Gorsky 1981) treat a definite description of the named person or object as a definition of the name. For example, ‘Napoleon Bonaparte is the person who was emperor of France from 1804 to 1814’ would be a definition of the name ‘Napoleon Bonaparte’. Such descriptions are accurate if and only if the description in context fits just the person or thing that the speaker intends to pick out by the name. One can introduce a name when one is uncertain about the existence of anything meeting the description one has in mind by using the term-forming epsilon operator introduced by the mathematical logician David Hilbert (Avigad and Zach 2020), which means roughly: the object or objects meeting the following description, if there are any.