Simple Categorical Syllogism The most important elementary type of syllogism. It consists of three categorical or attributive propositions so put together that the subject (t) and predicate (T) of the conclusion are united or separated through the intermediacy of a middle term (M).
1. Major term - predicate of the conclusion. It must occur in the conclusion and in one of the premises, generally the first called Major Premise.
2. Minor Term - subject of the conclusion. It must occur in the conclusion and is often introduced by the adversative conjunction "but".
3. Middle Term - occurs in each of the premises but not in the conclusion. *********************************** First proposition - Major premise Second proposition - Minor premise Third proposition - conclusion
Example: Every animal is mortal. But every dog is an animal Therefore, every dog is mortal.
HYPOTHETICAL SYLLOGISM It is a syllogism that has a hypothetical proposition as ine of its premises. 3 kinds of hypothetical syllogism, corresponding to the 3 kinds of hypothetical propositions.
1. The Conditional (if......, then.....) 2. The Disjunctive (either...., or......) 3. The Conjunctive (not both.., and...)
The conditional - one whose major premise is a conditional proposition. Conditional proposition is a compound proposition, of which one member asserts something as true on condition that the other member is true.
Examples: 1. If A, then C; but A; therefore C. 2. If A, then C; but not C; therefore not A. 3. If it is raining, then the roof is wet; But the roof is not wet Therefore, it is not raining.
Disjunctive syllogism - one whose major premise is a disjunctive proposition. Disjunctive proposition - present various alternatives and asserts that an indeterminate one of them is true. It is sometimes called alternative proposition.
Example: It is either raining or not raining; But is it raining Therefore, it is not raining.
Conjunctive syllogism - one whose major premise is a conjunctive proposition. Conjunctive proposition is one that denies the simultaneous possibility of two alternatives.
Example: You cannot be married and be single too; But he is married Therefore, he cannot be single.
