If you prefer a video version of this chapter, click below:

 

Vague and Ambiguous Video

 

 

Some disagreements are merely verbal, which means clearly defining terms can resolve such disagreements. Vague and ambiguous words lead to the most common types of verbal disagreement.

Vagueness refers to a lack of clarity in meaning. For example, Go down the road a ways and then turn right is vague because “a ways” does not precisely explain how far one should go down the road.

Ambiguity is when there is more than one clear meaning, and it is difficult to choose which meaning was intended. For example, Paul went to the bank is ambiguous because bank could mean a river bank or a financial institution. He was cut could mean he was cut from the team or he was cut by a sharp object.

Another example: The stool is in the garden is ambiguous because stool could mean poop or chair.

 

Exercise 1: Explain why these statements are vague.
1. I’ll be back later.
2. We should raise taxes on the wealthy.

Exercise 2: Explain why these statements are ambiguous.
1. The new pitcher is great.
2. I am renting the new apartment.

Exercise 3: Are the following statements ambiguous? Discuss/Explain.
1. Mother of eight makes a hole in one.
2. Kids make nutritious snacks.
3. God makes sense.

 

Answers: Later (2 hours or 2 days?), wealthy (50,000 or 100,000 or 1,000,000?), pitcher (container or baseball player?), renting (landlord or tenant?), Mother of eight (playing golf or put a hole in one of her children?), kids/snacks (kids make snacks or kids are the snacks?), God (God is logically consistent or God creates logic?). 

 

Application and Value
Precisely define your terms. This will reduce vagueness and ambiguity so that you are not talking past each other. It will also help you avoid the equivocation fallacy.

Logicians have taken this topic much further by identifying several fallacies of ambiguity (i.e. composition, division, equivocation, amphiboly, and accent), distinguishing ambiguity from indexicality, polsymey, and sense generality, comparing syntactic and semantic ambiguity, and exploring deeper issues related to this distinction.

*Thank you to Lawrence Pasternack at Oklahoma State University for some of the examples in this chapter.

Return to Logic Home                       Next (Chapter 10: Deductive & Inductive Arguments)