Clearly there is an epidemic of child abductions in this country. In the past year, major network news organizations have reported five cases of children who were abducted by strangers

1. [4 marks] For each of the following arguments: a) Identify the type of argument: enumerative induction or statistical syllogism. b) Indicate whether the argument is strong or weak. c) Explain why it’s strong or weak (whichever it is).

 

1. Clearly there is an epidemic of child abductions in this country. In the past year, major network news organizations have reported five cases of children who were abducted by strangers.

 

 

 

 

 

1. Professor Bill grew up in Sudbury, a small mining town. Most people who grow up in mining town have never read Plato. So, it’s very doubtful that Professor Bill has EVER read Plato.

 

 

 

 

 

 

 

 

2) (4 marks) For each statement, identify whether the statement is an A, E, I, or O

 

1. Some non-vegetarians are non-smokers.

 

1. Only males are bachelors.

 

• If it’s a dog, it’s an animal.

 

1. Socrates is not a Spartan.

 

 

 

3) For each statement, rewrite it so that it is in proper categorical statement form (5 marks)

 

1. If it’s worth doing, it’s worth doing right.

 

1. The Sun is a star around which our planet Earth revolves.

 

• None but 12-meter yachts are eligible for America’s Cup race.

 

1. The only good human is a dead human. [lifted from the Planet of the Apes!]

 

1. Only the brave are entitled to true love.

 

 

 

4) (4 marks) Convert the following statements and state whether the converse is logically equivalent:

1. All lawyers are extemporaneous speakers.
2. No lawyers are extemporaneous speakers.

• Some lawyers are extemporaneous speakers.

1. Some lawyers are not extemporaneous speakers.

 

 

5) (4 marks) Obvert the following statements, and state whether the obverse is logically equivalent.

1. All musicians are poets.
2. No musicians are poets.

• Some musicians are poets.

1. Some musicians are not poets.

 

 

 

 

6) (4 marks) Contrapose the following statements, and state whether the contraposition is logically equivalent.

 

1. All gothic cathedrals are buildings that feature pointed arches.
2. No gothic cathedrals are buildings that feature pointed arches.

• Some gothic cathedrals are buildings that feature pointed arches.

1. Some gothic cathedrals are buildings that do not feature pointed arches.

 

 

 

7) (20 marks) Example of how to do the following set of questions:

All A are B (F) [assume the statement is false]

Operation: contradictory [you are given this information]

New statement: Some A are not B

Truth value:  T

 

[i]

All non-A are B (T)

Operation: contraposition

New statement

Truth value

 

[ii]

Some A are non-B (F)

Operation:: subalternation

New statement

Truth value

 

[iii]

No A are non-B (T)

Operation: obversion

New statement

Truth value

[iv]

Some non-A are not B (T)

Operation: subcontrary

New statement

Truth value

 

 

[v]

No A are non-B (F)

Operation:  contradictory

New statement

Truth value

 

[vi]

No A are B (T)

Operation: contraposition

New statement

Truth value:

[vii]

All non-A are B (T)

Operation: contrary

New statement

Truth value

 

[viii]

Some A are not non-B (F)

Operation: obversion

New statement

Truth value

 

[ix]

No A are non-B (F)

Operation: conversion

New statement

Truth value

 

[x]

Some non-A are non-B (T)

Operation: subcontrary

New statement

Truth value

 

 

 

8) [6 marks] For the following passage (below), no attack is taking place. To the contrary!  But this is still an ad hominem.

 

1. How so?

 

1. Assuming Ralph’s argument is pure argument—an argument that we can understand completely—is this a fallacious ad hominem? Yes? No? Why?

 

• Assume Ralph’s argument is a bit over our heads (he’s an expert on the ins-and-outs of tax codes, and we are not). In this case, is the ad hominem fallacious? Yes? No? Why?

 

Ralph River argues that we should simplify the tax code. He argues that the complicated deductions are unfair to most Canadians, since only those who can afford an accountant are aware of them and can benefit from them. He also claims that they lead investors to focus on avoiding taxes rather than on investing their capital on developing solid industries that would provide good jobs. But Ralph, it so happens, is a highly paid accountant. Obviously if the federal tax code were simplified, he would stand to lose a lot of business. Yet he still argues for tax simplification! Since he is certainly not arguing just for his own narrow self-interest, we may consider his arguments to be that much more persuasive.

 

 

 

9) [6 marks] See the pdf attached, “appeal to authority”. For each of these two arguments [e] and [g], determine whether it is a legitimate or fallacious appeal to ignorance, and justify your answer. (Recall the list of necessary conditions of a legitimate appeal to ignorance, discussed in Class 6.)