PHL

Question 1

Hasty generalization (from too few cases)

Answer 1

arriving at a general statement or rule based on a sample that is too small.

Question 2

Argument by anecdote

Answer 2

taking a story about one case (or a small number) and drawing a unwarranted conclusion about it.

Question 3

Fallacy of the small sample

Answer 3

making a claim about the general population from a tiny sample.

Question 4

Generalizing from exceptional cases

Answer 4

arriving at a conclusion (generalization) based on a case that is in some way exceptional.

Question 5

Fallacy of biased sample

Answer 5

arriving at a conclusion (generalization) based ona sample that is skewed in some way.

Question 6

Fallacy of accident

Answer 6

When a speaker assumes that a general statement automatically applies to a specific case (that might very well be exceptional); also called the “fallacy of the general rule” and “destoring the exception.”

Question 7

Fallacy of weak analogy

Answer 7

an argument that draws a conclusion based on unimportant or debatable similarities between two things.

Question 8

Mistaken appeal to authority

Answer 8

When the speaker argues that you should believe a conclusion since it comes from a nonauthoritive source.

Question 9

Mistaken appeal to popularity

Answer 9

Arguing that public opinion about a matter us sufficent evidence in favor (or against) it.

Question 10

Mistaken appeal to common practice

Answer 10

arguing that a practice is justified because most people engage in it.

Question 11

Bandwagon fallacy

Answer 11

when a speaker tries to motivate the audience to go along with something so that they can be like everyone else (to go along with the crowd). This is the type of appeal to popularity that is more based on the psychological or emotional appeal of wanting to belong.

Question 12

Post hoc, egro propter hoc

Answer 12

“After this, therefore, because of it.” This is when a speaker assumes that the fact that one event came after another establishes that it was caused by it.

Question 13

Cum hoc, ergo propter hoc

Answer 13

“with this, therefore because of it.” When a speaker assumes that because two things happened at the same time, one thing must have caused the other.

Question 14

Slippery Slope

Answer 14

making an argument based on a warning that if you do one thing it will necessarily lead to some other (undesirable) thing without offering support for the claim that this progression will actually occur.

Question 15

Untestable Explanation

Answer 15

offering as proof a contention that could not possibly be tested.

Question 16

Formal fallacies

Answer 16

mistakes in reasoning that are due to the formal structure of the argument.

Question 17

Affirming the Consequent

Answer 17

If P then Q.
Q.
Therefore, P.

If Eli went trick or treating, then Eli received candy.
Eli received candy.
Therefore, Eli went trick or treating.

Question 18

Denying the Antecedent

Answer 18

If P then Q.
Not-P.
Therefore, not-Q.

If Marcy ate pine nuts, then Marcy got sick.
Marcy didn’t eat pine nuts.
Therefore, Marcy didn’t get sick.

Question 19

Fallacy of the Undistributed Middle

Answer 19

Occurs when a speaker assumes that two things related to a third thing are also related to each other.
This fallacy takes many forms, including:
All X are Y. All trees are plants.
All Z are Y. All flowers are plants.
Therefore, all X are Z. Therefore, all trees are flowers.

Question 20

Equivocation

Answer 20

an argument in which a word or phrase is used in two different ways within the same argument (related to semantic ambiguity)

Question 21

Amphilboly

Answer 21

When an argument is flawed because it relies on a syntactic ambiguity (ambiguity due to the structure of the sentence).

Question 22

Fallacy of Composition

Answer 22

Fallacy that occurs when someone believes that a feature that applies to some part of a thing can also be attributed to the thing as a whole.

Question 23

Fallacy of Division

Answer 23

When a speaker assumes that what is true of a group of things taken collectively must also be true of those same things taken as individuals (or assumes that what is true of a whole is true of its parts).

Question 24

Confusing explanation with excuses

Answer 24

when someone offers an explanation instead of providing an excuse or justification.

Question 25

Contradictories

Answer 25

Claims that never have the same truth value. If one claim is true the other must be false; if one claim is false the other must be true.

Question 26

Contraries

Answer 26

Two claims that cannot both be true, but that could both be false.

Question 27

Gambler’s Fallacy

Answer 27

This is when people make the mistake of not realizing that independent events really are independent.

Question 28

Overlooking Prior Possibilities

Answer 28

the prior probability is the probability of something happening “everything else being equal.”

Question 29

Faulty Inductive Conversion

Answer 29

This error occurs when a probability is calculated without looking at the people who were also a part of a certain group but not affected in the way being studied (mistakenly thinking that from the percentage of A’s that are B’s, you can derive a conclusion about the percentage of B’s that are A’s).

Question 30

Categorical logic

Answer 30

logic that concerns relations of membership in categories.

Question 31

Propostional logic

Answer 31

(“truth functional” logical) logic that concerns the relationship between statements, or claims.

Question 32

A

Answer 32

• Universal Affrirmative All S are P

Question 33

E

Answer 33

• Universal Negation No S are P

Question 34

I

Answer 34

• Particular Affirmative Some S are P

Question 35

O

Answer 35

• Particular Negation Some S are not P

Question 36

Conversion

Answer 36

switch the predicate terms
Statement Conversion
A All S are P All P are S
E No P are S No P are S
I some S are P Some P are S
O Some S are not P Some P are not S

Question 37

Obversion

Answer 37

Switch from aff/ neg and
Attach “non” to predicate the term*

    Statement		Obversion A	All S are P		No S are non-P E	No S are P		All S are non-P I	Some S are P	       Some S are not non-P O	Some S are not P	Some S are non-P

Question 38

Contraposition

Answer 38

Switch subject and predicate
Terms and attach “non” to each

Statement		Contraposition A	All S are P		All non-P are non-S E	No S are P 		No non-P  I	Some S are P O	Some S are not P