Square of Opposition - Exam #1

Question 1

What is the form of an A?

Answer 1

All S are P.

Question 2

What is the form of an E?

Answer 2

No S are P.

Question 3

What is the form of an I?

Answer 3

Some S are P.

Question 4

What is the form of an O?

Answer 4

Some S are not P.

Question 5

What quality is common to both A and E?

Answer 5

Universal.

Question 6

What quality is common to both I and O?

Answer 6

Particular.

Question 7

What quality is common to both A and I?

Answer 7

Affirmative.

Question 8

What quality is common to both E and O?

Answer 8

Negative.

Question 9

What letters are connected by contradiction, and by what truth relationship?

Answer 9

A and O, E and I. If one of them is true/false, the other must be the opposite.

Question 10

What letters are connected by contrariety, and by what truth relationship?

Answer 10

A and E. If one is true, the other must be false, but not vice versa.

Question 11

What letters are connected by sub-contrariety, and by what truth relationship?

Answer 11

I and O. If one is false, the other must be true, but not vice versa.

Question 12

What letters are connected by subalternation, and by what truth relationship?

Answer 12

A and I, E and O. If A or E is true, that I or O must be true respectively.

Question 13

What letters are connected by superalternation, and by what truth relationship?

Answer 13

A and I, E and O. If I or O is false, that A or E must be false respectively.

Question 14

How does conversion work, and what letters are connected by it?

Answer 14

Reverse the S and P.
I - I
E - E

(If true)
A - I
E - O

Question 15

How does obversion work, and what letters are connected by it?

Answer 15

Negate the copula, then the predicate.
A - E
E - A
I - O
O - I

Question 16

How does contraposition work, and what letters are connected by it?

Answer 16

First obvert, then convert, then obvert.
A - A
E - O
O - O

Question 17

What does Euler’s Circle for A look like?

Answer 17

A circle representing S inside a circle representing P.

Question 18

What does Euler’s Circle for E look like?

Answer 18

Two completely separate circles representing S and P.

Question 19

What does Euler’s Circle for I look like?

Answer 19

A Venn diagram with S on the left, P on the right, the outside of S as a dashed line, and X’s within the overlap.

Question 20

What does Euler’s Circle for O look like?

Answer 20

A Venn diagram with S on the left, P on the right, the left of the overlap as a dashed line, and X’s within the S-alone section.