Logical Equivalence
What phrase do we use to indicate that two statements are logically the same?
Logically Equivalent
Explain the steps in contraposition.
Logical equivalence made by obverting,
converting, and then obverting a statement
again
What is the antecedent?
This term refers to the first two propositions in
a syllogism
What is the Essential Law of Argumentation?
If the antecedent is true, the consequent must
also be true
What is the Middle Term?
The term that appears in both premises but
not in the conclusion
Give the two step method for obverting a statement.
1. Change the quality
2. Negate the predicate
Obvert the following sentence:
No men are immortal.
All men are not immortal. (mortal)
What is the consequent?
This term refers to the conclusion proposition
in a syllogism
What is a syllogism?
3 propositions ordered so that the
consequent is said to be necessarily inferred
from the antecedent
Which principles or dictum's does this syllogism illustrate?
All numbers have a value
0 has no value
Therefore, zero is not a number
PRNI, DO
Which of the four categorical statements can obversion be used?
A, E, I, and O
Convert the following sentence:
No bicycles are three-wheeled
No three-wheeled things are bicycles.
How do you find the Major Term?
The term that is the predicate of the
conclusion
What is the Major Premise?
The premise that contains the major term
Which principle or dictum does this syllogism illustrate?
No fish breath air
Nemo is a fish
Therefore, Nemo does not breath air
PRNI, DN
What is the rule of double negation?
A term which is not negated is equivalent to a
term that is negated twice
Contrapose the following statement:
All cars are fast.
All non-fast thing are not cars.
What is the Minor Term?
The term that is the subject of the conclusion
What is the Minor premise?
the premise that contains the minor term
Find the Major, Minor and Middle term.
God is perfect
Jesus is God
Therefore, Jesus is perfect
Major - perfect
Minor - Jesus
Middle - God
Explain the steps in conversion.
Logical equivalence made by interchanging
the subject and predicate of a statement
Who is Mr. Pritz's favorite student?
Nelle
What is the greatest sport in the world?
Wrestling
Label the minor, major and middle term:
All make-up is expensive
This classwork is make-up
Therefore, this classwork is expensive
Major: expensive
Minor: classwork
Middle: make-up
What is the major premise and the minor premise in this syllogism?
Some pineapples are under the sea
Spongebob's house is under the sea
Therefore, this pineapple is Spongebob's house
Major Premise: Spongebob's house is under the sea
Minor Premise: Some pineapples are under the sea