Syllogisms

This page illustrates syllogisms in three different ways:

With Venn diagrams, that show in which intersections of the three sets objects do not (black), can (white) or do (red) exist.
With Euler diagrams, which are like Venn diagrams with empty regions removed. (Only small diagrams on top of the table.)
The gist of this page is the reduction of this first-order logic topic to zeroth-order logic using binary square matrices that are essentially 8-ary logical connectives. There are 8 intersections of the three sets, and each intersection can either contain elements or not. So there are 2⁸ = 256 situations that can be the case. Each statement (premise or conclusion) can be denoted by the set of situations in which it is true.

All Syllogisms (table of contents)


1	Barbara	Barbari			Darii			Ferio	Celaront	Celarent
2								Festino	Cesaro	Cesare	Camestres	Camestros	Baroco
3				Darapti	Datisi	Disamis	Felapton	Ferison						Bocardo
4			Bamalip			Dimatis	Fesapo	Fresison			Calemes	Calemos

Graphical elements

Venn diagram and corresponding cubic Hasse diagram, used in the diagram on the right

The 256 situations that can be the case (minterms)
Light vertices indicate that an area is empty, dark vertices indicate that there is at least one element.