Analogy

[Resha Caner]

A is to B as C is to D, which can be written as A : B :: C : D

apple:apple tree :: pearear tree

Is this a valid analogy?

 

[GrowingSmaller]

Sorry I dont understand.

 

[mnorian]

A is to B as C is to D, which can be written as A : B :: C : D

apple:apple tree :: pearear tree

Is this a valid analogy?

-------------------------------------yes

 

[mnorian]

Israel : Christianity :: Israel : Islam
----------------------------------------
Valid analogy?

 

[Resha Caner]

Israel : Christianity :: Israel : Islam

Valid analogy?

What's with all the dashes? Anyway, you're jumping ahead. Let's come back to that one.

yes

OK. But what if Eve is using this analogy to try to convince Adam that all fruits are equally good for eating? Adam is not convinced. He prefers pears because that's what he's been eating all his life, and he doesn't like to try new things.

apple:apple tree :: pearear tree

Is it still a valid analogy?

 

[mnorian]

What's with all the dashes? Anyway, you're jumping ahead. Let's come back to that one.



OK. But what if Eve is using this analogy to try to convince Adam that all fruits are equally good for eating? Adam is not convinced. He prefers pears because that's what he's been eating all his life, and he doesn't like to try new things.

apple:apple tree :: pearear tree

Is it still a valid analogy?

---------------------------------------------
You are adding outside elements into your analogy that were not there in the first page: illogical. Sort of like one of those British mysteries that challenges you to figure out the mystery but in the final scene adds new elements(clues) to the mix.
And the dashes are lines; helps me to type straight.

 

[Resha Caner]

You are adding outside elements into your analogy that were not there in the first page: illogical. Sort of like one of those British mysteries that challenges you to figure out the mystery but in the final scene adds new elements(clues) to the mix.

Right. The claimed relationship is the fruit to the tree, not the fruit to Adam. You can't use the analogy for one relationship to claim something about another relationship. That's a fallacy.

So, how about this one then -

apple:apple tree :: grapes:grapevine

 

[2PhiloVoid]

Right. The claimed relationship is the fruit to the tree, not the fruit to Adam. You can't use the analogy for one relationship to claim something about another relationship. That's a fallacy.

So, how about this one then -

apple:apple tree :: grapes:grapevine

almost?

 

[Resha Caner]

apple:apple tree :: grapes:grapevine

almost?

Yeah. we're getting into intent now. The validity of the analogy depends on the intent of the one who uses it. A grapevine is not a tree. So, if the claim is used to infer something about the class of objects in the analogy, it is wrong. In other words, if it is trying to infer apple tree and grapevine are both in the "tree" class, that is a fallacy. However, if the relationship is only about fruit bearing plants, it would still be valid.

Analogies should make no claim regarding the relationships A : C, A : D, B : C, or B : D.

So what about this then -

apple:apple tree :: soapberry:wingleaf tree(*)

For those who don't know, the soapberry is the poisonous fruit of the wingleaf tree.

 

[2PhiloVoid]

Yeah. we're getting into intent now. The validity of the analogy depends on the intent of the one who uses it. A grapevine is not a tree. So, if the claim is used to infer something about the class of objects in the analogy, it is wrong. In other words, if it is trying to infer apple tree and grapevine are both in the "tree" class, that is a fallacy. However, if the relationship is only about fruit bearing plants, it would still be valid.

Analogies should make no claim regarding the relationships A : C, A : D, B : C, or B : D.

So what about this then -

apple:apple tree :: soapberry:wingleaf tree(*)

For those who don't know, the soapberry is the poisonous fruit of the wingleaf tree.

Yes, if we are inferring the relationship of fruit to its parent tree; but No, if we are trying to compare edible to inedible fruits.

[So...where are we going with the analogy stuff, Resha?]

 

[Resha Caner]

Yes, if we are inferring the relationship of fruit to its parent tree; but No, if we are trying to compare edible to inedible fruits.

Correct.

So...where are we going with the analogy stuff, Resha?

The subtlety of rhetoric and debate. I'm curious how much people here know about it. It's only one of many details, but analogies are used here all the time, and they are often dismissed by opponents as inapplicable or irrelevant. I'm just curious how familiar people are with formal logic and its subtle uses.

For example, what about this one: Two people are having a debate about the founding fathers of the American republic, and someone makes the following statement -

Washington:American federalism :: Mussolini:Italian fascism

So. Is that a valid analogy or not?

And we can now circle back to mnorian's question -

Israel : Christianity :: Israel : Islam
----------------------------------------
Valid analogy?

 

[2PhiloVoid]

Correct.



The subtlety of rhetoric and debate. I'm curious how much people here know about it. It's only one of many details, but analogies are used here all the time, and they are often dismissed by opponents as inapplicable or irrelevant. I'm just curious how familiar people are with formal logic and its subtle uses.

For example, what about this one: Two people are having a debate about the founding fathers of the American republic, and someone makes the following statement -

Washington:American federalism :: Mussolini:Italian fascism

So. Is that a valid analogy or not?

And we can now circle back to mnorian's question -

...my inclination would be to say 'invalid,' but I'm willing to be shown otherwise.

 

[Resha Caner]

...my inclination would be to say 'invalid,' but I'm willing to be shown otherwise.

Don't worry. The "wrong" answer won't force you to accept every iota of my theology as infallible. It's important to the discussion to know why you think it's invalid.

 

[quatona]

A is to B as C is to D, which can be written as A : B :: C : D

apple:apple tree :: pearear tree


Is this a valid analogy?

Yes.

OK. But what if Eve is using this analogy to try to convince Adam that all fruits are equally good for eating? Adam is not convinced. He prefers pears because that's what he's been eating all his life, and he doesn't like to try new things.

Completely irrelevant for the analogy.

apple:apple tree :: pearear tree

Is it still a valid analogy?

Yes.

 

[essentialsaltes]

Washington:American federalism :: Mussolini:Italian fascism

When doing these kind of SAT style analogies (which have since been dropped from the test), the key is to express a clear and necessary relationship between the first two items. If you can do the same for the second two items, it is a valid analogy.

The apple is the fruit of the apple tree.
The soapberry is the fruit of the wingleaf tree.

This is a valid analogy. But the connection in the analogy only extends to 'is the fruit of'. It does not refer to edibility or poisonousness.

Washington was a founding exponent of American federalism.
Mussolini was a founding exponent of Italian fascism.

Looks valid.

But SAT analogies are not really what one uses rhetorically. Or at best, they are just a beginning upon which to hang additional judgments and accountrements.

 

[2PhiloVoid]

Don't worry. The "wrong" answer won't force you to accept every iota of my theology as infallible. It's important to the discussion to know why you think it's invalid.

Well, then. I think the analogy fails because I do not see that Washington necessarily stood in the same influential relationship 'role wise' to American Federalism as Mussolini did to to Italian Fascism. But again, perhaps my understanding of the respective political history is 'off,' so I'm willing to be shown otherwise.

 

[Resha Caner]

Completely irrelevant for the analogy.

Fair enough. The point was that Eve was attempting something invalid in formal logic.

 

[Resha Caner]

Well, then. I think the analogy fails because I do not see that Washington necessarily stood in the same influential relationship 'role wise' to American Federalism as Mussolini did to to Italian Fascism. But again, perhaps my understanding of the respective political history is 'off,' so I'm willing to be shown otherwise.

When doing these kind of SAT style analogies (which have since been dropped from the test), the key is to express a clear and necessary relationship between the first two items. If you can do the same for the second two items, it is a valid analogy.

The apple is the fruit of the apple tree.
The soapberry is the fruit of the wingleaf tree.

This is a valid analogy. But the connection in the analogy only extends to 'is the fruit of'. It does not refer to edibility or poisonousness.

Washington was a founding exponent of American federalism.
Mussolini was a founding exponent of Italian fascism.

Looks valid.

Right. So you have accepted the relationship "was a founding exponent", but Philo hasn't. It's not my purpose to debate who is right or wrong, but it is one problem with formal analogies. If one opponent won't accept the relationship, the analogy (valid or not) isn't going to help.

But SAT analogies are not really what one uses rhetorically. Or at best, they are just a beginning upon which to hang additional judgments and accountrements.

Very true. People often use analogies like this for an informal purpose ... and informal logic is (I think) a very interesting subject. If you know your opponent is a great admirer of Washington and federalism, what might you expect his opinion to be of Mussolini and fascism?

 

[mnorian]

@Resha Caner
----------------------------------
Here is one for you:

Rules of Debate : Philosophy :: Rules of Debate : Faith based conversion
-----------------------------------------------------------------------------------
Valid analogy?

 

[mnorian]

Correct.



The subtlety of rhetoric and debate. I'm curious how much people here know about it. It's only one of many details, but analogies are used here all the time, and they are often dismissed by opponents as inapplicable or irrelevant. I'm just curious how familiar people are with formal logic and its subtle uses.

For example, what about this one: Two people are having a debate about the founding fathers of the American republic, and someone makes the following statement -

Washington:American federalism :: Mussolini:Italian fascism

So. Is that a valid analogy or not?

And we can now circle back to mnorian's question -

Israel : Christianity :: Israel : Islam
----------------------------------------
Valid analogy?

--------------------------------------------
As no one answered this: invalid. Christianity was grafted into the tree of Israel by God while Islam was man-made.