Critical Thinking and Logic 4.5

27 flashcards

In the traditional square of opposition, what is the topmost line?

Contrary

In the traditional square of opposition, what is the bottom line?

Subcontrary

In the traditional square of opposition, at least one (if not both) of A and E must be?

False

In the traditional square of opposition, at least one (if not both) of I & O must be?

True

Truth trickles

downwards

Falsity flows

upwards

In the Aristotelian viewpoint, if the subject is non-existent (for sure), examine using

the MODERN square of opposition

Conditionally valid

Taken as and probably is true, but has a chance of being false.

If an incorrect inference is made on E using A (or vice versa) in terms of their contrary relationship, the fallacy is called

Illicit contrary fallacy

If an incorrect inference is made on I using O (or vice versa) in terms of their subcontrary relationship, the fallacy is called

Illicit subcontrary fallacy

From the Aristotelian viewpoint, the A venn diagram would have/be:

Shading on the left, an x in the middle

From the Aristotelian viewpoint, the E venn diagram would have/be:

Shading in the middle, an x on the left

If an A categorical proposition is converted and stated to be true, it commits the

Illicit conversion fallacy

What are the vertical processes in the traditional square of opposition called?

Subalternation

If an I proposition is true, and one infers that an A proposition is true, that inference would be....

Invalid, commits illicit subalternation fallacy

If an A proposition is true (on the traditional square), we can infer that the E proposition is...

false

If an I proposition is false (on the traditional square), we can infer that that the O proposition is...

true

All cats are animals. Some cats are animals. From the Boolean pov, this is....

Invalid, existential fallacy

All cats are animalsSome cats are animals From the Aristotelian pov this is...

Valid

All unicorns are animalsSome unicorns are animals From the Aristotelian pov this is...

INVALID, existential fallacy

All unicorns are animalsSome unicorns are animals From the Boolean pov this is...

Invalid, existential fallacy

existential fallacy (from the Aristotelian pov)

when contrary, subcontrary, and subalternation are used (in an otherwise correct way) to draw a conclusion from a premise about things that do not exist.

The existential fallacy (from both views) is committed when going from a(n) ------- to a(an) -----

Universal to a particular

All cats are dogs.Therefore, some cats are dogs. From the Aristotelian pov, this statement is -----, but not ----

Valid, but not sound

Remember, for assessing validity, we assume the premises to be -----

true

Given the statement: All non-A are FTherefore, some F are not A How many steps (and which) would need to be taken to prove this right?

3: subalteration, conversion, and obversion