Categorical Statements
Give the standard form of an A-statement.
All S are P
In which type of statement is only the subject distributed?
A Statement
Which pair cannot both be true and cannot both be false?
Contradictions.
How many statements are in a syllogism?
3
Which rule is broken if a syllogism contains four terms?
Rule 1
Identify the form: "Some dogs are pets."
I Statement
Which statement distributes both terms?
E Statement
What is the contradiction of “All S are P”?
Some S are not P
Name the three terms of a syllogism.
Major Term
Middle Term
Minor Term
Which rule states that the middle term must be distributed at least once?
Rule 3
What type of statement is “Some athletes are not swimmers”?
O Statement
Is the predicate distributed in an I-statement?
No — both subject and predicate are undistributed.
What is the subcontrary of “Some S are P”?
Some S are not P
Identify the mood:
All M are P
Some S are M
∴ Some S are P
AII
What fallacy occurs when a term undistributed in the premise becomes distributed in the conclusion?
Rule 4
Translate into standard categorical form: "Not all birds fly."
Some birds are not flyers.
Identify distribution in: “Some cats are not mammals.”
Subject = undistributed; Predicate = distributed.
If a universal statement is true, what does sub-implication tell us about its particular?
The particular must also be true.
Identify the figure:
All P are M
No S are M
∴ No S are P
Figure 2
What rule is broken with two negative premises?
Rule 5
Translate: “Whenever a creature is a whale, it is a mammal.”
All whales are mammals.
Determine distribution in: “No philosophers are non-thinkers.”
Both terms distributed (E-statement).
“Some S are P” is true. State the truth values:
All S are P
No S are P
Some S are not P
Undetermined
False
Undetermined
Identify mood, figure, and validity:
All P are M
All M are S
∴ All S are P
AAA-4, invalid (Rule 4)
Identify the rule violated:
All dogs are animals.
Some pets are dogs.
∴ All pets are animals.
Rule 4