Imagine a school where no one can wear a red hat. John goes to school with a red hat costing 5 dollars. Someone says John's red hat "is" the reason why he can't get into the school.
What is the function of "is" here? Can we say the reason that John couldn't get into the school costs 5 dollars?
In one sense we can say whatever we want, the question is to what end. On the shades of meaning associated with "is" see What is the difference between the "is" of predication and the "is" of identity? But the "fault" here does not lie with "is" exactly. It is the substitution play with the "red hat" that does violate some semantic rules, although one could also say that the use of "is" (unusually) does not license the substitution.
"Red hat" in "the reason John couldn't get into the school is his red hat" is a stand-in for something else, it is not the red hat that is (literally) the reason but the breaking of the school's policy. Indeed, red hats and reasons are not even in the same category, the former are concrete objects, the latter are relational abstractions. It is said that the use of "red hat" is metaphoric, and metaphoric contexts are opaque. This means that one can not substitute co-referential expressions into them because metaphorical use does not rely on common reference, see opaque contexts. Similarly, we can not substitute "abstract noun" into "he tasted freedom", even though freedom is an abstract noun. An extreme case of this would be to exploit homonymy to replace "he was hit with a bat" by "he was hit with a mammal".
This said, many philosophers dispute that the literal/metaphoric distinction is legitimate, and we can take "the reason that John couldn't get into the school costs 5 dollars" as just another metaphoric use. It is baffling and humorous, so why not? People do make such uses, e.g. when talking about "putting a price on someone's head". Here is from Davidson's What Metaphors Mean:
"All communication by speech assumes the interplay of inventive construction and construal. What metaphor adds to the ordinary is an achievement that uses no semantic resources beyond the ordinary resources on which the depends. There are no instructions for devising metaphors; there is no manual for determining what a metaphor "means" or "says"; there is no test for metaphor that does not call for taste... The central mistake against which I shall be inveighing is the idea that a metaphor has, in addition to its literal sense or meaning, another sense or meaning...
The concept of metaphor as primarily a vehicle for conveying ideas, even if unusual ones, seems to me as wrong as the parent idea that a metaphor has a special meaning. I agree with the view that metaphors cannot be paraphrased, but I think this is not because metaphors say something too novel for literal expression but because there is nothing there to paraphrase."
Another reason John could not attend school; policy, which prohibits attending school with red hats, right or wrong. Causes of policies are other reasons. 'The'refore i would say it is wrong to say "the reason" he could not attend school costed 5 dollars. Many reasons exist; "the reason" seems to mean one reason only or in essence the reason was buying a red hat. A reason costed 5 dollars. It is partly about a (not the) difference between dialectical philosophy, about essence in "the", and non-reductionist philosophy without "essence". Non-reductionist philosophies ascribe reasons to many aspects, not only one essence. I think non-reductionist philosophy is closer to Truth. We were falsely indoctrinated to think dialectically. Writing shows it. I first had "the difference" above. Then i changed it to "a difference". Would not be surprised if "then" is another word after "the" disappearing. "The" has to do with dialectical philosophy of theology, which is changing. This philosophy is called Intequinism.
Absolutely yes.
Our perception of macroscopic nature imply that we interact in order to live (an interaction is an atomic exchange of contents between two systems, see my last book if you're interested). If I had invited you for a beer in exchange of advice, it is clear that we've exchanged something. The beer was a physical entity, the advice a logical entity (see a hierarchy of entities in [1]). Imagine that the beer costed me 5$, and I was happy to pay for it. You was also happy. Both can agree that the exchange was fair.
That doesn't mean, objectively, that an advice costs 5$. But in this particular case, the advice does costed 5$, subjectively (for each subject). We have the natural habit of giving value to any type of entity, and money is just one form of value. Every minute, in family, society, Internet, etc. we exchange advice, love, cars, guitars, gossip, etc.
Of course, usually, we don't speak of the value of each content we interchange, we just know it (that's what our learning is about since childhood: we learn to weight interactions, what we give and what we receive, when to exchange and when to avoid interactions, when to repeat them or when to reject people that causes us loss after interaction).
No one tells his girlfriend "I invite you for a dinner of 51.99$ in exchange of 33:19 minutes of sex". But the fact is that subjectively, such value could be extremely profitable for both partners. And they could be so happy that they could repeat the interaction several times. Even if both had never thought of the exchange in such sordid way.
[1] What would be the correct abstraction for Thing and Action?
A cleverly and wittily phrased question. I like it and hope for more of the same. My answer is, 'no', though. Here's why.
The cost of the hat has nothing to do with the situation. The school has a rule that no-one can - may - wear a red hat. This is, I assume, a rule known by John in advance. You don't say but I take it this is the case. John goes to school wearing a hat that cost $5 - or $50 for that matter - and paid for by himself or someone else.
John is prevented or otherwise disallowed from entering the school wearing his red hat. John's hat (this material object) isn't the kind of thing that can be a reason for anything - at least in this context. He is kept out of school because he has broken a rule, one that happens to be about hats. Because he is wearing a red hat and because wearing such a hat breaks a school rule, therefore he is prevented or otherwise disallowed from entering the school. The red hat is just an inert object that can't constitute any sort of reason. The reason involved is John's wearing a forbidden item to school.
