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Hi Friends;

I can not get the meaning of this sentence:

Let "w" be the predicate: to be a predicate that cannot be predicated of itself.

What is the meaning of "be predicated of" here?

And, what is the whole meaning of the sentence?
Would you help me?


Thanks.

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anonymousbe predicated of

~ be said about

Examples:

Being triangular cannot be predicated of historical events.
~ You can't say "It is triangular" when speaking of the Civil War.

Telling a lot of funny jokes cannot be predicated of raspberries.
~ You can't say "They tell a lot of funny jokes" when speaking of raspberries.


anonymousLet "w" be the predicate: to be a predicate that cannot be predicated of itself.

It's saying this:

Let "w" be this predicate:
is a predicate that cannot be predicated of itself.

Of course, this is going to lead you down a rabbit hole from which you may never return. Emotion: big smile

CJ

Comments  

You should link to the whole thing. This is less an English question than a math question:

https://en.wikipedia.org/wiki/Russell%27s_paradox

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 CalifJim's reply was promoted to an answer.
John Smith 3141 This is less an English question than a math question:

Agreed, it is a technical statement related to Russell's Paradox in logic/mathematics, but I would still be interested to see an explanation of how, in the logic they were discussing, a predicate can be predicated of something. According to search results thrown up, Frege (one of the main protagonists) is quoted as saying "it seems to me that the expression 'a predicate is predicated of itself' is not exact. A predicate is as a rule a first-level function, and this function requires an object as an argument and cannot have itself as an argument".

GPYhow ... a predicate can be predicated of something.

I guess I'm missing some of the technicalities.

It seems to me that the whole point of predicates (is a boy; went shopping; explained the theorem) is that they are predicated of something.

George (is a boy); Glenda (went shopping); The professor (explained the theorem)

'is a boy' is a predicate, and it can be predicated of George.
'went shopping' is a ...

Well, you get the idea.

CJ

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CalifJimIt seems to me that the whole point of predicates (is a boy; went shopping; explained the theorem) is that they are predicated of something.

The quote refers to a predicate that can't be predicated of itself, so I suppose in ordinary language such a predicate could be something like "is a predicate in the French language", i.e. it is not true that:

"is a predicate in the French language" is a predicate in the French language.

However, the original quote is not talking about predicates in ordinary language but predicates in a certain kind of logic, so the question I had was whether the predicates referred to can strictly speaking be predicated (or not predicated) of themselves, according to the rules of that logic.

GPYThe quote refers to a predicate that can't be predicated of itself, so I suppose in ordinary language such a predicate could be something like "is a predicate in the French language", i.e. it is not true that: "is a predicate in the French language" is a predicate in the French language.

Yes. That's a good example of how I see it as well.

GPYHowever, the original quote is not talking about predicates in ordinary language but predicates in a certain kind of logic

I suspect these predicates may be expressed in the symbols of mathematical logic, but I believe these sequences of symbols do correspond to ordinary language predicates in some way or another.

GPYwhether the predicates referred to can strictly speaking be predicated (or not predicated) of themselves, according to the rules of that logic.

I suspect that depends on what the postulates of that particular logic system are. In fact, wasn't that part of the great discussions during the first part of the 20th century? Should a system of logic allow it or not? At some point Goedel gets involved and blows the lid off the whole thing. At least that's my wacky version of it from popular culture.

CJ