Cora Diamond

“The understanding of a person who talks nonsense uses the type of linguistic
construction that we use when we understand someone who talks sense. “You are
under the illusion that p” is modeled on “You believe that p”. But sentences with
that structure, all of them, make sense only when they contain, in the clause giving
the content of what is believed or thought or denied or said or whatever, an
intelligible sentence. “You are under the illusion that p” does not do that. It is
essential, then, to what is going on in the case of understanding a person who talks
nonsense that you use a sentence-structure which gives a sentence with a sense only
when what it contains in its “that” -clause is a sentence that makes sense; and you
want to fill it in with a sentence that makes no sense. You want the type of sentence
suitable for internal understanding of sense; and yet it is exactly that sort of sentence
that will be nonsensical in the circumstances for which you want it. But, as I said,
remaining outside, and just talking about how the person puts together words and
associates with them feelings and so on, would not give you what you want. To want
to understand the person who talks nonsense is to want to enter imaginatively the
taking of that nonsense for sense. My point then is that the Tractatus, in its
understanding of itself as addressed to those who are in the grip of philosophical
nonsense, and in its understanding of the kind of demands it makes on its readers,
supposes a kind of imaginative activity, an exercise of the capacity to enter into the
taking of nonsense for sense, of the capacity to share imaginatively the inclination tonthink that one is thinking something in it. If I could not as it were see your nonsense
as sense, imaginatively let myself feel its attractiveness, I could not understand you.
And that is a very particular use of imagination.”
― Cora Diamond, The Realistic Spirit: Wittgenstein, Philosophy, and the Mind

“The understanding of a person who talks nonsense uses the type of linguistic construction that we use when we understand someone who talks sense. “You are under the illusion that p” is modeled on “You believe that p”. But sentences with that structure, all of them, make sense only when they contain, in the clause giving the content of what is believed or thought or denied or said or whatever, an intelligible sentence. “You are under the illusion that p” does not do that.
It is essential, then, to what is going on in the case of understanding a person who talks nonsense that you use a sentence-structure which gives a sentence with a sense only when what it contains in its “that” -clause is a sentence that makes sense; and you want to fill it in with a sentence that makes no sense. You want the type of sentence suitable for internal understanding of sense; and yet it is exactly that sort of sentence that will be nonsensical in the circumstances for which you want it. But, as I said, remaining outside, and just talking about how the person puts together words and associates with them feelings and so on, would not give you what you want. To want to understand the person who talks nonsense is to want to enter imaginatively the taking of that nonsense for sense.
My point then is that the Tractatus, in its understanding of itself as addressed to those who are in the grip of philosophical nonsense, and in its understanding of the kind of demands it makes on its readers, supposes a kind of imaginative activity, an exercise of the capacity to enter into the taking of nonsense for sense, of the capacity to share imaginatively the inclination to think that one is thinking something in it. If I could not as it were see your nonsense as sense, imaginatively let myself feel its attractiveness, I could not understand you. And that is a very particular use of imagination.”
― Cora Diamond