1. 5 Categorical Syllogisms
5.2 Venn Diagrams

2. Venn Diagrams
For testing Standard Form Categorical Syllogisms we add a circle for the middle term M S P S P

3. Venn Diagrams Follow this procedure diagramming arguments:
Marks are made only for premises
Diagram universal premises first (if both, any order)
Concentrate on the 2 circles talked about in the premise you are diagramming
When reading a diagram, remember that particular statements assert 2 things (existence and location)
When shading, be sure to shade the entire area
Xs go on the line in an area that is unshaded, otherwise they go in the area the shading leaves open
Xs never go on the intersection of 2 lines, and never go on the outside of the circles

4. Venn Diagrams
1 No P are M (see p.246) All S are M No S are P S P M

5. Venn Diagrams
2 All M are P No S are M No S are P S P M

6. Venn Diagrams
3 Some P are M All M are S Some S are P S P M

7. Venn Diagrams
Skip a few…

8. Venn Diagrams
5 Some M are P All S are M Some S are P S P M

9. Venn Diagrams
8 Some M are not P Some S are M Some S are not P S P M

10. Venn Diagrams (Aristotelian Standpoint)
No F are T
All F are C
Some C are not T
Step 1:
Diagram as usual using Boolean Standpoint S P M

11. Venn Diagrams (Aristotelian Standpoint)
No F are T
All F are C
Some C are not T
Step 2:
Put an X in any circle with just one empty area S P M

12. Venn Diagrams (Aristotelian Standpoint)
No F are T
All F are C
Some C are not T
Step 3
Determine whether circled X represents something that actually exists. If it does, the argument is valid from the Aristotelian Standpoint S P M