1. Definitions
February 8th, 2016

2. administrative stuff
The extension of a term consists of the entities to which it applies
Fictional terms have an empty extension
Some non-fictional terms also have an empty extension (‘living velociraptors’)

3. 2.3 Definitions
DEFINITION - a group of words that assigns a meaning to some other word or group of words.

4. 2.3 Definitions
The definiendum is the word or group of words that is supposed to be defined.

5. 2.3 Definitions
The definiendum is the word or group of words that is supposed to be defined. The definiens is the word or group of words that does the defining.

6. 2.3 Definitions
The definiendum is the word or group of words that is supposed to be defined.
The definiens is the word or group of words that does the defining.
Example
Cat: A small, domesticated carnivorous mammal with soft fur, a short snout, and retractile claws

7. 2.3 Continued
Stipulative definitions assign a new meaning to a word

8. 2.3 Continued Stipulative definitions assign a new meaning to a word
Stipulative definitions are often created in response to some new phenomenon or development.

9. 2.3 Continued Stipulative definitions assign a new meaning to a word
Stipulative definitions are often created in response to some new phenomenon or development.
Examples are “tigon” for the offspring of a male tiger and a female lion, and “liger” for the offspring of a male lion and a female tiger.

10. 2.3 Continued Stipulative definitions assign a new meaning to a word
Stipulative definitions are often created in response to some new phenomenon or development.
Examples are “tigon” for the offspring of a male tiger and a female lion, and “liger” for the offspring of a male lion and a female tiger.
Stipulative definitions are also used to assign meaning to codewords

11. 2.3 Continued
Lexical definitions report a meaning that a term already has in a language

12. 2.3 Continued
Lexical definitions report a meaning that a term already has in a language
Dictionary definitions are all lexical definitions; terms often have multiple definitions.

13. 2.3 Continued
Lexical definitions report a meaning that a term already has in a language
Dictionary definitions are all lexical definitions; terms often have multiple definitions.
As a consequence, lexical definitions can be right or wrong, relative to the community of discourse they are supposed to apply to.

14. 2.3 Continued
Lexical definitions report a meaning that a term already has in a language
Dictionary definitions are all lexical definitions; terms often have multiple definitions.
As a consequence, lexical definitions can be right or wrong, relative to the community of discourse they are supposed to apply to.
If I define ‘professor’ as ‘a five-headed dragon’, I will be incorrect.

15. 2.3 Lexical Definitions
Lexical definitions also serve to distinguish among multiple meanings of words that can be used in different ways.

16. 2.3 Lexical Definitions
Lexical definitions also serve to distinguish among multiple meanings of words that can be used in different ways. (e.g., light = not heavy, pale-colored, a form of radiation)

17. 2.3 Continued
Precising definitions reduce vagueness

18. 2.3 Continued Precising definitions reduce vagueness
Defining “poor” as “having an annual income of less than $10,000 and a net worth of less than $20,000” is a precising definition.

19. 2.3 Continued Precising definitions reduce vagueness
Defining “poor” as “having an annual income of less than $10,000 and a net worth of less than $20,000” is a precising definition.
Precising definitions reduce vagueness for a specific context.

20. 2.3 Continued
Theoretical definitions assign meaning to terms according to a theoretical framework. They offer a way to understand a phenomenon via that framework.

21. 2.3 Continued
Theoretical definitions assign meaning to terms according to a theoretical framework. They offer a way to understand a phenomenon via that framework.
You often run into theoretical definitions in the context of scientific or philosophical discussion

22. 2.3 Continued
Theoretical definitions assign meaning to terms according to a theoretical framework. They offer a way to understand a phenomenon via that framework.
You often run into theoretical definitions in the context of scientific or philosophical discussion
“Heat” means the energy associated with the random motion of the molecules of a substance.

23. 2.3 Continued
Theoretical definitions assign meaning to terms according to a theoretical framework. They offer a way to understand a phenomenon via that framework.
You often run into theoretical definitions in the context of scientific or philosophical discussion
“Heat” means the energy associated with the random motion of the molecules of a substance.
“God” means whatever uncaused cause put the universe into motion.

24. 2.3 Continued
Persuasive definitions engender a particular attitude

25. 2.3 Continued Persuasive definitions engender a particular attitude
This is done by assigning an emotional or value-laden meaning to a word while making it appear that the word really has (or ought to have) that meaning in the language in which it is used.

26. 2.3 Continued Persuasive definitions engender a particular attitude
This is done by assigning an emotional or value-laden meaning to a word while making it appear that the word really has (or ought to have) that meaning in the language in which it is used.
E.g., “Capitalism is the economic system in which humanity is sacrificed to the wanton quest for money, and mutual respect is replaced with greed and alienation.”

27. 2.5 Criteria for Lexical Definitions

28. 2.5 Criteria for Lexical Definitions
Conform to proper grammatical standards
Grammar is the bones of language, a structure that greatly contributes to the whole.

29. 2.5 Criteria for Lexical Definitions
Conform to proper grammatical standards
Grammar is the bones of language, a structure that greatly contributes to the whole.
Convey essential meaning
If you define “human” as a featherless biped, then plenty of non-cases will count as human, and plenty of real humans will be excluded

30. 2.5 Criteria for Lexical Definitions
Conform to proper grammatical standards
Grammar is the bones of language, a structure that greatly contributes to the whole.
Convey essential meaning
If you define “human” as a featherless biped, then plenty of non-cases will count as human, and plenty of real humans will be excluded
Be neither too broad nor too narrow
Your definition of “bird” should exclude bats, which are mammals, and include ostriches, which cannot fly.

31. 2.5 Continued Avoid circularity
Makeup is a product used by people to make themselves up.

32. 2.5 Continued Avoid circularity Be affirmative (where possible)
Makeup is a product used by people to make themselves up.
Be affirmative (where possible)
Normally you would say that “‘Concord’ means harmony,” but you can use conventional usage for such definitions: “ ‘Dark’ is the absence of light.”

33. 2.5 Continued Avoid circularity Be affirmative (where possible)
Makeup is a product used by people to make themselves up.
Be affirmative (where possible)
Normally you would say that “‘Concord’ means harmony,” but you can use conventional usage for such definitions: “ ‘Dark’ is the absence of light.”
Avoid figurative, obscure, vague or ambiguous language
Camels are a species of mammal, not “ships of the desert.”

34. 2.5 Continued
Avoid affective terminology, such as sarcasm and facetiousness
“Theism” means belief in that great Santa Claus in the sky.

35. 2.5 Continued
Avoid affective terminology, such as sarcasm and facetiousness
“Theism” means belief in that great Santa Claus in the sky.
Indicate proper context
“Strike” means different things in the contexts of baseball, bowling, fishing, and war.

36. To Review 5 kinds of definitions: Stipulative Lexical Precising
Theoretical
Persuasive

37. To Review 5 kinds of definitions:
Stipulative
Lexical
Precising
Theoretical
Persuasive
What kind is the following definition?

38. To Review 5 kinds of definitions:
Stipulative
Lexical
Precising
Theoretical
Persuasive
What kind is the following definition?
“Nausea is a sensation that is associated with illness and that often leads to vomiting.”

39. To Review 5 kinds of definitions:
Stipulative
Lexical
Precising
Theoretical
Persuasive
What kind is the following definition?
Let’s use “bimboy” to describe a boy who’s a total airhead.

40. To Review 5 kinds of definitions:
Stipulative
Lexical
Precising
Theoretical
Persuasive
What kind is the following definition?
“Politician” means a person of unquestioned honesty and integrity whom the people, in their collective wisdom, have duly elected to guide the ship of state and protect it from the reefs and shoals that threaten it on every side.”

41. To Review 5 kinds of definitions:
Stipulative
Lexical
Precising
Theoretical
Persuasive
What kind is the following definition?
“Blind means, for federal income-tax purposes, either the inability to see better than 20/200 in the better eye with glasses or having a field of vision of 20 degrees or less.”

42. Practice With a partner, come up with lexical definitions for:
Restaurant
Zebra
Grief
You have five minutes!