G M Second figure: All good citizens love their country, S M No criminal loves his country, S G ∴ No criminal is a good citizen. G ― M S ― M ――――― S ― G M G Third figure: All good citizens are law abiding, M S All good citizens vote, S G ∴ Some who vote are law abiding. M ― G M ― S ――――― S ― G G M Fourth figure: Some teachers are fair minded, M S All who are fair minded are just, S G ∴ Some just persons are teachers. G ― M M ― S ――――― S ― G Here, then, are the types that represent all the syllogisms which mediate inference may use. _Logic recognizes no other._ Since every successful student of logic must be familiar with the four figures, the following may be used as a suggestive aid to reproducing the figures at will: First. It is easy for any one to remember this syllogism: All men are mortal, Socrates is a man, ∴ Socrates is mortal. In fact, it comes down to us from the time of Aristotle, and is therefore a patriot of many generations to whom the faithful should touch their hats. Let us, then, be ready to reproduce this syllogism with automatic precision, since it will enable us to know at once the _position of the terms_ in the first figure. Second. Converting the terms of the _major premise_ of the first figure gives the second figure, as, e. g.: First figure. Second figure. M ― G (Convert) G ― M S ― M S ― M ――――― ――――― S ― G S ― G Third. Converting the terms of the _minor premise_ of the first figure gives the third figure, as, e. g.: First figure. Third figure. M ― G M ― G S ― M (Convert) M ― S ――――― ――――― S ― G S ― M Fourth. Converting the terms of _both the major and minor premises_ of the first figure gives the fourth, as, e. g.: First figure. Fourth figure. M ― G (Convert) G ― M S ― M (Convert) M ― S ――――― ――――― S ― G S ― G