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Chapter 12

# Philosophy 1230A/B Chapter Notes - Chapter 12: Categorical Logic

Department
Philosophy
Course Code
PHIL 1230A/B
Professor
Jonathan Marsh
Chapter
12

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Categorical Logic
-Formulated by Aristotle 2000 years ago
-Basic Unit: statement component. We study the relationships between subject and predicate
Four things to know for categorical logic:
1) The nature of categorical statements
2) How to construct and translate formal categorical statements
3) How to combine those categorical statements into categorical syllogisms
Categorical Statements
Their nature: statements that make assertions about categories, or classes, of things.
(Let S= frogs; p= animals)
-A-statement All S are P (Universal affirmative)
E-statement No S are P (Universal negative)
I statement Some S are P (Particular affirmative)
O Statement Some S are not P (Particular negative)
Their parts:
1. Quantifier (All/None/Some)
2. Subject Term (e.g frogs)
3. Copula (Are/are not)
4. Predicate term (e.g. animals)
A few simple steps
Step 1. Identify the terms and ensure they designate a class (e.g. animals)
Step 2. Distinguish subject term from predicate term (former always comes first)
Step 3. Perform any necessary rewording
Step 4. Don’t forget the copula
Example. All roses are red
Translation: All roses are red flowers
Original: Some guys have all the luck
missing the copula, no predicate term
Translation: Some guys are people who have all the luck
Original: No U.S. states are in Canada
Translation: No U.S. states are places identical with places in Canada
1. All elected officials are civil servants
2. All politicians are elected officials
3. All politicians are civil servants
………
1. All m are p s=politician, p=civil servants, m=elected officials