Part 5 (2/2)

_Universal Negative_, symbolized by ”E.”

_Particular Affirmative_, symbolized by ”I.”

_Particular Negative_, symbolized by ”O.”

It will be seen that these four forms of Judgments bear certain relations to each other, from which arises what is called opposition.

This may be better understood by reference to the following table called the Square of Opposition:

A CONTRARIES E +------------------------+

/

/S

C /E

O /I

N /R

T /O

S

R /T

S U

A /C

U B

/I

B A

/D

A L

/

L T

/

T E

/ D

E R

/ I

R N

/A C

N S

/R T

S

/T O

/N R

/O I

/C E

/ S

/

+------------------------+ I SUB-CONTRARIES O

Thus, A and E are _contraries_; I and O are _sub-contraries_; A and I, and also E and O are _subalterns_; A and O, and also E and I are _contradictories_.

The following will give a symbolic table of each of the four Judgments or Propositions with the logical symbols attached:

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