Syllogism

Types of Categorical Proposition

  

All S are P	Universal Affirmative
No S is P	Universal Negative
Some S are P	Particular Affirmative
Some S are not P	Particular Negative

Venn-diagram Representation of Four Propositions

         1.    Universal Affirmative : All S are P : here there are two possible diagrams one is whole S is inside P(i.e. S<P) and other is S and P  in  same circle (i.e. S=P)

     

           

        2.    Universal Negative: No S is P: here there is only one possible diagram that S and P are separate circles.

        3.    Particular Affirmative: Some S is P: here there are three possible diagrams First is P inside S, Second is S inside P and third is S and P both are partially overlapping with each other. 
 

        4.    Particular Negative: Some S is not P: here also there are three possible diagrams First is P inside S, Second is S and P are separate and third is S and P both are partially overlapping with each other. 

     
       Note: basics of syllogism are explained, for possibility type of question you have to draw all possible diagrams for that conclusion.  viewers are requested to put some questions for discussion.