William of Sherwood's Introduction to Logic (1966), p. 33
by of Sherwood, William; Kretzmann, Norman (ed.)

Copyright according to our policy

Caption

A "hexagon of opposition" combining what seem to be Sherwood's own observations with those he derives from Aristotle

Logic

Aristotelian family

Sherwood-Czeżowski Sigma-3

Boolean complexity

4

Number of labels per vertex (at most)

1

Uniqueness of the vertices up to logical equivalence

Yes

Errors in the diagram

No

Geometry

Shape

Hexagon (irregular)

Colinearity range

0

Coplanarity range

0

Cospatiality range

0

Representation of contradiction

By central symmetry

Vertex description

Conceptual info

No

Mnemonic support (AEIO, purpurea ...)

No

Form

none

Label type

linguistic

Language

English

Lexical field

syllogistics

,

singular propositions

Contains partial sentences or single words

No

Contains abbreviations

No

Edge description

Contains definitions of relations

No

Form

solid lines

Has arrowheads

No

Overlap

No

Curved

No

Hooked

No

As wide as vertices

No

Contains text

Yes

Label type

linguistic

Language

English

Contains partial sentences or single words

Yes

Contain abbreviations

No

Style

Diagram is colored

No

Diagram is embellished

No