Lecture Notes © 2008 McGraw Hill Higher Education

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Critical Thinking

Chapter 4

Language

Lecture Notes © 2008 McGraw Hill Higher Education

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The Need for Precision Without precision, one cannot be correctly understood. Lack of understanding or misunderstanding hinders discussion,

dialogue, and debate. In fact, misunderstandings are quite often the causes of

disagreements. For example, suppose that both you and I know that Bob committed a certain crime and that his trial has not occurred yet. I might say: • (1) “Bob is guilty” Now (1) can mean two things:

• (a) He committed the crime.• (b) He has been convicted of the crime.

• If I mean (a), but you think I mean (b) we will say we disagree about whether (1) is true, when in fact we share the same beliefs (we both think he did it and know that he hasn’t been convicted yet). But not until I clarify what I mean by (1) will this fact become evident.

But when you can’t be understood, it is not the other person’s fault. If others can’t understand you, you need to be more precise!

Lecture Notes © 2008 McGraw Hill Higher Education

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Ways to be un-precise

Vagueness• Borderline cases

Overgenerality• Too general; too many things fit the

description of the answer and thus the answer is not useful.

Ambiguity• A word is ambiguous when it has more than

one common definition.

Lecture Notes © 2008 McGraw Hill Higher Education

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Vagueness A word (or group of words) is vague when its

meaning is inexact. Usually you can tell a word is vague when

there are borderline cases. • minimal pay, middle-aged, indecent, obscene, etc.

In each of these cases, there are clear cut cases (20 is not middle aged, and neither is 80, but 45 is), but there are examples where it is unclear (like 33 or 56).

In some venues it is appropriate, but usually try to avoid it, especially in argumentation.

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Overgenerality

An overgenerality is a statement that provides too much information to be useful (in a given context).

They will not be vague (i.e., they won’t give rise to borderline cases), but will not be useful. • Example of a overgeneral answer:

• Q: “What is 7+5?” A: “More than 2.”

Context is relevant: • “Human” is an alright answer to a question about your

chess opponent (which could be a computer), but not a question about your new fiancé.

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Ambiguity A word or expression is ambiguous if it has two or more

meanings and the context does not make clear which meaning is intended. • “Ambi” means “both”; a word that is ambiguous has two

meanings, but can’t “mean” both at the same time. Semantic Ambiguities: Ambiguities that result from

uncertainty about the meanings of an individual word or phrase• e.g., Joe went to the bank.

• (What kind of bank? Financial Institution? A slope that boarders a river? A blood bank?)

Syntactical Ambiguities: ambiguity due to sentence structure or faulty grammar. • “Dog for sale. Eats anything and is especially fond of

children.”

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Types of Disputes Verbal Dispute: occurs when people appear to disagree on

an issue, but in actuality have simply not resolved the ambiguity of a key term.• A disagreement about “Steve loves Mary.”

• Steve: Of course I love you! • (Steve thinks “I love you” means “I get ‘warms feelings’ when I think

about you.”)

• Mary: No, you don’t love me! • (Mary thinks, “I love you” means “I don’t want to be with anyone else.”)

They agree about the facts (they both know that Steve gets warm feelings, but that he wants to see other people), they just are using a different definition of the word “love.”

Factual Dispute: Disagreements where people actually disagree about the facts. • O.J. killed Anna Nicole! • No he didn’t!

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Precise Definitions Types of Definitions:

• Stipulate Definitions• Persuasive Definitions• Lexical Definitions• Precising Definitions

Strategies for Defining• Ostensive Definitions• Enumerative Definitions• Definitions by Subclass• Etymological Definitions• Synonymous Definitions• Definition by Genus and Difference

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Reasons for Defining Stipulative definitions: When you create a definition for a

new word (or use an existing word in a new way, and set forth that new use), you have stipulated a new definition.

Persuasive Definitions: Defining a term to convince someone of something. • Capital Punishment means vengeful murder.

Lexical Definitions: state the conventional, dictionary meaning (derived from how it is commonly used).

Precising Definitions: taking a vague word/phrase and clarifying what you mean by it (in a certain context) (i.e., taking a vague word and making it more precise).

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Strategies for Defining Ostensive Definitions: physically identifying the definition

of a word/term.• Example: These are parentheses: ( )

Enumerative Definitions: listing examples of individual things that “fit” the definition: • “Bible-belt state” means Texas, Oklahoma, Arkansas, and the

like. • Such definitions are very useful but can be misleading; someone

might identify a commonality in your examples you didn’t foresee. • “oh, bible-belt State” means “Southern states west of the Mississippi.”

Definition by Subclass: listing examples of classes or categories that “fit” the definition. • Mammal means gorilla, horse, lion, whale, human, etc. • Such definitions are very useful but can be misleading for the

same reasons as above.

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Strategies for Defining Etymological Definitions: definitions that articulate the

history of a word’s use or its origins. Synonymous Definitions: defining a term by giving a

synonym for which the definition is known. • “Loquacious means talkative.”

• These are helpful but sometimes imprecise; • e.g., “rob” and “steal” are synonyms, but have slightly different

definitions. Definition by Genus and Difference: defining a term by

identifying its class and then differentiating it from other members in the class. • Calf is young cow; i.e., a cow (genus) that is young

(difference).