Syllogisms
True or False?
Examples
Definitions
Square of Opposition
100

Is this a valid syllogism?

OEA-1

Invalid, any syllogism with two negative premises is invalid.

100

True or false, a consequent is the result in a hypothetical statement  (follows "If...")

TRUE! 

100

AAA, EAE, ......

Mood

100

What is the mood and figure of a syllogism?

Form

100

Four types of statements represented by the square of opposition

A, E, I, O universal aff. and neg, particular aff. and neg

200

Is this a valid syllogism?

OOA - 3

invalid - two negative premises

200

True or false? A number form from 1 to 5 identifying the placement of the syllogism's middle term is called the figure.

FALSE! Only 4 forms 

200

If P, then Q.

Hypothetical statement 

200

What is a statement that affirms an outcome based on a condition?

Enthymeme

200

The relationship between A and O and I and E statements

Contradiction - opposite truth values

300

What is the middle term in the following syllogism?

All men are mortals.

No mortals are angels.

Therefore, some angels are not men.  

mortals

300

True or False, a syllogism is sound if it has valid premises.

False! A syllogism is sound if it has true and valid premises

300

whoever, whatever, wherever, whenever, however, always

Inclusive

300

What is an argument that uses only hypothetical statements?

Pure hypothetical syllogism

300

Relationship between universal A and E statements


Relationship between particular I and O statements

Contrariety - both can be false but can't both be true


Subcontrariety - both can be true but they both can't be false

400

Is this a valid syllogism?

All whales are mammals.

No canaries are mammals.

Therefore, some canaries are not whales.

Valid - if the conclusion is negative, one premise must be negative

400

True or False, a syllogism is an inductive argument that contains to premises and 1 conclusion.

FALSE. It is a deductive argument not inductive

400

follows if .....

Antecedent

400

What is a term , within a statement, that refers to all members of this class/category?

Distributed term

400

Relationship between a universal and particular statement of the same quality. The truth of the universal requires the truth of the particular

Subimplication - between A and I and E and O statements

500

Is this syllogism valid?

Some M is P

Some S is M

Therefore, No S is P

Invalid - illicit major, illicit minor, undistributed middle, two affirmative premises and a negative conclusion

500

True or False, a contrapositive statement reverses and negates both the subject and predicate of the original only in A and O statements.

TRUE

500

only, nobody but, nothing but, unless, except

Exclusive

500

A syllogism with the same form as the original, but with obviously true premises an an obviously false conclusion, in order to show the original to be invalid.

Counterexample

500

Relationship between the universal and particular statements of the same quality in which the falsity of the particular requires the falsity of the universal

Superimplication

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