Deck 11: Deductive Reasoning

Question 1

All conservatives favor small government. Colleen favors small government. Therefore, Collen is a conservative. This syllogism is:

A) Valid
B) Invalid; undistributed middle term
C) Invalid; four term rule
D) Invalid; affirming the consequent
E) Denying the antecedent

Answer 1

B

Question 2

In formal logic, an argument in which the conclusion necessarily follows from the premises, if the premises are true, refers to:

A) An enthymeme
B) A syllogism
C) The Toulmin model
D) An inductive argument

Answer 2

B

Question 3

Soundness refers to a syllogism in which:

A) The premises are true
B) The conclusion is valid
C) The premises are true, but the conclusion is not valid
D) The conclusion is valid, but the premises are not true
E) The premises are true, and the conclusion is valid

Answer 3

E

Question 4

The three basic types or forms of the syllogism are:

A) Universal, conditional, nonconditional
B) Categorical, conditional, disjunctive
C) Valid, invalid, and unsound
D) True, false, uncertain

Question 5

All guys who like bowling enjoy beer. Chuck is a guy who likes bowling. Therefore, Chuck enjoys beer. This syllogism is:

A) Valid
B) Invalid
C) Sound
D) Invalid by affirming the consequent
E) Invalid by denying the antecedent

Question 6

All squares have four sides. Some rectangles have four sides. Therefore, some squares are rectangles. This syllogism is:

A) Valid
B) Invalid (undistributed middle term, four sides)
C) Valid, but unsound
D) Probably valid
E) Probably invalid

Question 7

A categorical syllogism has:

A) One term
B) Two terms
C) Three terms
D) Four terms
E) 1-4 terms

Question 8

All men are human beings. All women are human beings. Therefore, all men are women. This syllogism is:

A) Valid
B) Invalid; illicit major
C) Invalid; illicit minor
D) Invalid; undistributed middle term
E) Invalid; existential fallacy

Question 9

A restaurant owner makes the following deductive argument: "If our food is too spicy, then customers would complain. Customers have complained. Therefore, our food is too spicy." The owner's argument is most accurately described as:

A) Affirming the consequent (invalid)
B) Denying the antecedent
C) Affirming the antecedent
D) Denying the consequent

Question 10

A restaurant owner makes the following deductive argument: "If our food is too spicy, then customers would complain. Customers have not complained. Therefore, our food is not too spicy." This syllogism is:

A) Valid; affirming the antecedent
B) Invalid; denying the antecedent
C) Invalid; affirming the consequent
D) Valid; denying the consequent

Question 11

Some A are B.All C are D. Therefore, some A are D. This syllogism is:

A) Valid
B) Invalid (violates the four term rule)
C) Unsound
D) Fallacious

Question 12

No horned mammals are carnivores. All rhinos are horned mammals. Therefore, no rhinos are carnivores. This syllogism is:

A) Valid
B) Invalid
C) Unsound
D) Fallacious

Question 13

All cyclops are one-eyed. Some trolls are not one-eyed. Therefore, some trolls are not cyclops. This syllogism is:

A) Valid
B) Invalid; affirming the consequent
C) Invalid; denying the antecedent
D) Invalid; undistributed middle term
E) Sound

Question 14

Jane is either a soccer fan or she is a basketball fan. Jane is not a basketball fan. Therefore, Jane is a soccer fan. This syllogism is:

A) Valid
B) Invalid
C) Unsound
D) Fallacious

Question 15

Which statement about the validity and soundness of syllogisms is most accurate?

A) If a conclusion is valid, it must be sound.
B) If a conclusion is sound, it must be valid. (Validity is a prerequisite for soundness.)
C) A conclusion that is valid cannot be sound.
D) If a conclusion is unsound, it cannot be valid.
E) A conclusion can be sound whether it is valid or not.

Question 16

All parrots have feathers. Some pets are parrots. Therefore, some pets have feathers. This syllogism is:

A) Valid
B) Invalid; illicit major
C) Invalid; illicit minor
D) Invalid; affirming the consequent
E) Denying the antecedent

Question 17

Which of the following accurately describes "soundness" as it relates to syllogisms?

A) The premises are true
B) The conclusion is true
C) The conclusion is valid
D) The premises are true, and the conclusion is valid
E) The premises may or may not be true and the conclusion is valid

Question 18

Darlene laments, "It's Friday night. Either I stay home and wish I went out, or I go out and wish I stayed home." What type of syllogism has Darlene offered?

A) Categorical
B) Disjunctive
C) Subjunctive
D) Conditional
E) Abjective

Question 19

That bird is either a raven or a crow. Ravens have dense, shaggy plumage. That bird has dense, shaggy plumage. Therefore, that bird is a raven. This syllogism is:

A) Valid
B) Invalid
C) True
D) False (more than four terms, more than three premises)

Question 20

All snakes that are venomous are carnivorous. All snakes that are constrictors are carnivorous. Therefore, all snakes are carnivorous. This syllogism is:

A) Valid
B) Invalid (the middle term, carnivorous, is not distributed, and it appears in the conclusion)
C) True
D) False

Question 21

All English muffins have nooks and crannies. All bagels have holes in the middle. Therefore, no English muffin is a bagel. This syllogism is:

A) Valid
B) Invalid; violates the four term rule
C) Invalid; no universal conclusion
D) Invalid; two negative premises

Question 22

All gun owners are supporters of the Second Amendment. All supporters of the Second Amendment are left-handed. Therefore, all gun owners are left-handed. This syllogism is:

A) Invalid
B) Unsound* (the form is valid, but the premises are untrue)
C) Untrue
D) Fallacious

Question 23

Identify the valid conclusion that can be drawn from the premises below: Some X are not Y. All X are Z. Therefore,

A) Some Z are not Y
B) No X is Y
C) Some Z are not X
D) No Y is X

Question 24

All Dutch people are from Holland. All people from Holland wear wooden shoes. Therefore, all Dutch people wear wooden shoes. This syllogism is:

A) Valid
B) Invalid
C) Sound
D) Untrue
E) Fallacious

Question 25

Identify the valid conclusion that can be drawn from the premises below. No fans of polka music are Russians All Germans are fans of polka music Therefore,

A) Some Germans are not fans of polka music
B) Some Russians are fans of polka music
C) No Russians are fans of polka music
D) All Russians and Germans have different tastes in music

Question 26

Consider the deductive argument below: God is love. Love is blind. Stevie Wonder is blind. Therefore, Stevie Wonder is God. This syllogism is:

A) True
B) Valid
C) Invalid (More than four terms, more than two premises)
D) Sound

Question 27

Explain the difference between validity and soundness as it applies to a categorical syllogism. Provide an example or examples to demonstrate your answer.

Question 28

Virgil states, "Form logic is useless in everyday life." Is he right? Why or why not?

Question 29

What is a categorical syllogism? How can you tell if a categorical syllogism is valid? How can you tell if a categorical syllogism is sound?

Question 30

Provide an original example (not found in the text) of each of the three types of syllogisms: categorical, conditional, disjunctive.