How do you define cohesion and coherence?
One definition of coherence is "The set of relationships within a text that link sentences by meaning." And one definition of cohesion is "Grammatical or lexical relationships that bind different parts of a text together."
Yes, exactly.
In the novel example, "Dracula," "Frankenstein," and "Gothic novels" form a hypernymy/hyponymy relationship, thereby satisfying the criterion of cohesion.
Yes.
Whatever is wrong with the example cannot be related to cohesion.
I don't follow this. The hyponymy relationship is not relevant in any way.
The cohesion problem I'm talking about is what I thought you were describing as a mismatch of number—precisely the problem that we're talking about! There is an issue with grammatical cohesion between the plural books and the singular this. I thought that's what you were saying, no?
What is the coherence problem in this case?
The coherence problem is that when the reader reads
this thrilling book, it doesn't make sense. He doesn't know how to understand what the phrase is referring to. That's a coherence problem. You know all this, so why are you asking me to waste time explaining this to you?
I have a feeling that you are not actually interested in my answer, so this will be the last post I offer. If you are interested, read my previous posts again, more carefully.
Attributing the problem to "mismatch of number" is merely restating the problem rather than solving it.
First, well, actually it's just a way of describing the problem grammatically. Second, no, it is no way solving any problem. Why do you think it might be? What do you mean by solving the problem? I think you must have misunderstood something here.
The thread is all about why some shifts in number are allowed and some are not.
I wouldn't use the word 'allowed', but okay, yes, sure, we know that.
The answer I'm giving you is simple: if it's clear what the speaker/writer is referring to (like in the
instrument example), it's allowed. If it's really unclear and confusing (like in the novels example), it's not allowed. Another way to say that is that if it makes sense it's okay and if it doesn't make sense, it's not. Another way to say that is if it's coherent, it's fine and if it's not, it's not. That's the best 'rule' that you're going to get.
I'm looking for a principled, precise, and non-circular explanation.
Look, I don't know how to be any more clear. Nothing I've said can be described as circular. If you think so, you've misunderstood. Reread the whole thread again.