1. Chapter 3
Logic and Language

2. Preview of 3.1 - 3.3 Problem areas 3.1 3.2 3.3 Proposition
Subtlety of definitional terms
3.3
Largely unproblematic

3. Chapter 3.1 This chapter is about “What is actually meant by . . . .”
Which of these concepts/terms were difficult?
Proposition
Cognitive meaning
Emotive force
For the concepts/terms that were confusing, can someone clarify it for us by defining and giving at least one example, or the range of examples, of it?
Why is it important to understand these concepts/terms?
Review problematic exercises

4. Chapter 3.2 Which of these concepts/terms were difficult?
Ambiguity versus vagueness
Extensional definition
Ostensive
Enumerative
Subclassical
Intensional definition
Lexical (genus & differentia)
Stipulative
Precising
Theoretical
For the concepts/terms that were confusing, can someone clarify it for us by defining and giving at least one example, or the range of examples, of it?
Why is it important to understand these concepts/terms?
Review problematic exercises

5. Why care about definitions?
‘Define’ literally means to put ‘limits around’ (fr. L. de ‘about’ + finis ‘limit’).
So, definition limits meanings.
Minimizes
vagueness (meanings shading off into other areas)
ambiguity (more than one meaning)
Minimizes complications of “It all depends on what you mean by __________.”

6. Definition by extension
Pointing (a.k.a. ‘ostensive’)
actually showing one or more cases
Enumeration
listing individual examples
Subclass
listing types or categories
Exhaustive v. non-exhaustive?

7. Intensional definition
Stipulative: personal, ad hoc, coined or not
Lexical: positive, descriptive, dictionary-type, though not necessarily exclusively so
Precising: minimizes vagueness & ambiguity, to “put a fine point on it,” to distinguish precise meaning from popular meaning
Theoretical: places a term in a particular context; may give meaning to both term and context
Persuasive: affective, subjective, emotive

8. Definition by intension
Synonym
Another word (lit.  ‘similar’ +  ‘name’)
Etymology
Linguistic genealogy (lit.  ‘true’ + s ‘account’)
Test
Establishes criteria to be met
Genus + difference/differentia
“garden variety” definition technique: ‘x is a y [that ]’

9. Chapter 3.2, cont’d. Which of these concepts/terms were difficult?
Genus versus difference/differentia
Definiendum versus definiens
Counterexample
For the concepts/terms that were confusing, can someone clarify it for us by defining and giving at least one example, or the range of examples, of it?
Why is it important to understand these concepts/terms?
What are the criteria for producing a good definition?
Not to wide
Not to narrow
Not obscure, ambiguous, figurative
Not circular
Not negative if it can be positive
Not use unsuitable criteria to determine extension
Review problematic exercises

10. Ways of defining: terms
‘definiendum’: word to be defined
‘definiens’: words doing the defining
‘extension’: set of objects in defined class
‘intension’: properties of objects in class

11. Rules
What is meant by essential characteristics (necessary & sufficient)?
How can the definiens be too broad or narrow?
What is meant by circularity?
Cite examples of ambiguity, obscurity, figurative or emotive language.

12. Chapter 3.3 Which of these concepts/terms were difficult?
Equivocation versus merely verbal dispute
Persuasive definition
For the concepts/terms that were confusing, can someone clarify it for us by defining and giving at least one example, or the range of examples, of it?
Why is it important to understand these concepts/terms?
Review problematic exercises