Homework from last time: diagramming arguments

5. God is all-powerful, all-loving, and all-knowing. Since God is all-powerful, he has the capacity to rid the world of evil. Since God is all-knowing, he has the capacity to know where and when evil occurs. Since God is all loving, he wants to get rid of evil in the world. However, there is evil in the world. Thus, God does not exist.

Homework from last time: diagramming arguments

(1) God is all-powerful.(2) God is all-loving.(3) God is all-knowing. (4) Since God is all-powerful, he has the capacity to rid

the world of evil. (5) Since God is all-knowing, he has the capacity to know

where and when evil occurs. (6) Since God is all loving, he wants to get rid of evil in

the world. (7) However, there is evil in the world. (8) Thus, God does not exist.

Homework from last time: diagramming arguments

(1)+ (4) + (2) + (5) + (3)+ (6)There shouldn’t be any evil + (7)

(8)

Homework from last time: diagramming arguments

6. Some things that exist are caused by other things. Nothing can be the cause of itself. Nor can there be an endless string of objects causing other objects to exist. Therefore, there must be an uncaused first cause: God.

Homework from last time: diagramming arguments

(1) Some things that exist are caused by other things.

(2) Nothing can be the cause of itself. (3) Nor can there be an endless string of objects

causing other objects to exist. (4) Therefore, there must be an uncaused first

cause: God.

Homework from last time: diagramming arguments

(1) + (2) + (3)(4)

Homework from last time: diagramming arguments

8. In Star Wars (Episode IV: A New Beginning), Darth Vader boards Princess Leia’s ship and has the following conversation with a member of the crew:

Vader: Where are those transmissions you intercepted?Rebel: We intercepted no transmissions. This is a

consular ship. We’re on a diplomatic mission.Vader: If this is a consular ship, where is the

ambassador? Rewrite Darth Vader’s argument, and diagram it.

Homework from last time: diagramming arguments

(1) If this were a consular ship, the ambassador would be on it.

(2) But the ambassador is not on the ship.(3) Thus, it is not a consular ship but a rebel

ship.(1) + (2)

(3)

Homework from last time: diagramming arguments

9. Rewrite King Arthur’s argument, and diagram it. Then rewrite the soldier’s argument, and diagram it.

Homework from last time: diagramming arguments

(1) We found the coconuts here.(2) While this is a temperate zone, coconuts grow in

the tropics.(3) However, birds in temperate zones migrate to

tropical zones and back.(4) One of those migratory birds could have carried

a coconut back by gripping its husk.(2) + (3) + (4)

(1)

Homework from last time: diagramming arguments

(1) This is a temperate zone, but coconuts grow in the tropics.

(2) Birds in temperate zones migrate to tropical zones and back.

(3) Migratory birds are too small to carried a coconut back.

(4) Thus, King Arthur can’t have found the coconut here.

(1) + (2) + (3)(4)

The Language of Arguments

Phil 57 section 3San Jose State University

Fall 2010

Diagramming, evaluating arguments:

Sometimes half the battle is figuring out exactly what the argument is claiming.

Language can be messy.

Ambiguity

• Some words or expressions have more than one distinct, nonoverlapping meanings.

The loud music made the prisoner mad.(Mad = angry or crazy?)

All men are created equal.(Men = human beings or adult males?)

Ambiguity

• Sometimes sentence structure can make meaning ambiguous.

"I met a man with a wooden leg named Smith”."What was the name of his other leg?”

Ambiguity from sentence structure:

"I shot an elephant in my pajamas. How he got in my pajamas I don't know."

"Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read."

Vagueness:

Some expressions have clear applications (e.g., pregnant, unique, true), but others have borderline cases:

old, young, tall, short, bald, tired, rich, happy, hot, cold, close, far, …

Vagueness:

He has a lot of friends. Facebook lists more than 600 friends for him.

What does “friends” mean here? (Do Facebook friends count?)

Definitions as a way to remove ambiguity and vagueness.

Different ways to define terms.

Ostentive definition: point out the thing you’re defining.

“This is a Rick Roll.”

Definitions as a way to remove ambiguity and vagueness.

Different ways to define terms.Verbal extensional definition: select members

of the set you’re defining.“Schools in the Cal State University system – San

Jose State, San Francisco State, Cal State-East Bay, Cal State-Chico, Cal State-LA, …”

“Domestic animals – cats, dogs, rabbits, chickens, goats, …”

Definitions as a way to remove ambiguity and vagueness.

Different ways to define terms.Intensional definition: sets out the properties of

members of the set you’re defining.Lexical definition: a description of how the term

is commonly used (as in dictionary def’n)“Cud” means “the portion of food that a

ruminant returns from the first stomach to the mouth to chew a second time.”

Definitions as a way to remove ambiguity and vagueness.

Lexical definition: can be a problem if they are too narrow (i.e., include properties that aren’t essential to the thing being defined) or too broad (i.e., leave out properties essential to the thing being defined).

“Dog” means “a four-legged animal.”

“Light bulb” means “an incandescent electric light.”

Definitions as a way to remove ambiguity and vagueness.

Different ways to define terms.Intensional definition: sets out the properties of

members of the set you’re defining.Stipulative definition: description of how a

brand new term should be used.“The Internet” means “a vast computer network

linking smaller computer networks worldwide.”

Definitions as a way to remove ambiguity and vagueness.

Different ways to define terms.Intensional definition: sets out the properties of

members of the set you’re defining.Precising definition: a description of how an

otherwise vague term is meant“Full-time student” means “a student with a

course load of at least 12 units a semester.”

Definitions as a way to remove ambiguity and vagueness.

Different ways to define terms.Intensional definition: sets out the properties of

members of the set you’re defining.Theoretical definition: description of how a

term should be used assuming a particular theory.

“Centigrade” is the temperature scale on which water freezes at zero and boils at 100.

Sometimes definitions convey extra information.

Persuasive definitions express approval or disapproval (“emotive force”) for the thing picked out by the term being defined.

“A hipster is someone trying way too hard to be cool while trying to look totally unconcerned about being cool.”

Operational definitions:

Give practical instructions about how to tell if an expression describes an object or situation.

The “hard-crack stage” has been reached when a spoonful of hot syrup dropped into a bowl of very cold water forms brittle threads and cracks if you try to mold it.

Homework:

1. In an SNL skit from many years ago, two workers at a nuclear power plant are arguing about the meaning of a sign on the wall of their control room that says, “You can’t have too much water in a nuclear cooling tank.” (Later, after things at the reactor go wrong, they argue over the safety manual that says, “You can’t look too long at a nuclear blast.”) Explain the ambiguity in these two instructions (e.g., by spelling out the two different ways one might interpret each sentence).

Homework:

3. The novelist Lois Duncan is a young adult author. Lois Duncan is also 76 years old. Discuss what is vague about the term “young adult author” and give a definition that removes the vagueness.

Homework:

5. Explain what’s wrong with each of these lexical definitions:

a. “Politically” means “in a political manner.”c. “Fork” means “ a utensil for eating foods.”d. “Whale” means “an aquatic mammal.”

Homework:

7. Give a verbal extensional definition for “pizza toppings.” Discuss the limits of this definition (e.g., in conveying information to someone who doesn’t already have a clear understanding of what pizza is).

Homework:

8. For each of the following pairs of terms, identify whether there is a difference in emotive force between the members of the pair, and whether both members of each pair have the same intensional meaning (i.e., whether they refer to the same things):

a. Fragile – weakb.Public servant – bureaucrat

Homework:

8. For each of the following pairs of terms, identify whether there is a difference in emotive force between the members of the pair, and whether both members of each pair have the same intensional meaning (i.e., whether they refer to the same things):

c. Native American – Indiand.Sweat – perspire

Homework:

8. For each of the following pairs of terms, identify whether there is a difference in emotive force between the members of the pair, and whether both members of each pair have the same intensional meaning (i.e., whether they refer to the same things):

e. Chairman – chairpersonf. Cop – police officer

Homework:

8. For each of the following pairs of terms, identify whether there is a difference in emotive force between the members of the pair, and whether both members of each pair have the same intensional meaning (i.e., whether they refer to the same things):

g. Boy – young manh. Waiter – waitress

Homework:

10. Formulate an operational definition for “awake” in “The students in the lecture are awake.”