Heh. I taught my phone "Kimhi" but it ignored me this time. — Srap Tasmaner
(A) "Dogs are nice"
and on the other
(B) "For all x, if x is a dog, then it is nice."
We just need a neutral word for the relation between (A) and (B), and, if you start with (A) and recast it as (B), we need a neutral word to describe what you're doing there. Maybe you believe you are "revealing (A)'s logical form," and maybe you don't. — Srap Tasmaner
Again, for me it begins with the puzzle of the Meno. I want to say that if logic is artifice then knowledge is artificial. And of course some of what we involve ourselves in when we do logic is artifice, but that doesn't mean that there is nothing more than that involved. — Leontiskos
One of the problems here is that focusing on Frege may give the false impression that his account remains paradigmatic for modern logic. It isn't.From what I understand, in the Begriffsschrift "⊢" is an explicit judgement; what follows is known, while — would prefix "a mere complex of ideas", un-affirmed (SEP). In the Grundgesetze this has changes significantly; ⊢ now says something like "The following names the true" (SEP). That's much closer to it's modern use, where ⊢ρ is "ρ is a theorem" and ψ⊢ρ says "ρ is derivable from ψ". Notice that in these more recent uses, truth is not mentioned. That's important. — Banno
So far as my previous posts on this page, I was making the point that we can talk about our utterances with greater lucidity that about our thoughts, simply because our utterances are public. — Banno
One of the problems here is that focusing on Frege may give the false impression that his account remains paradigmatic for modern logic. It isn't. — Banno
But earlier Leontiskos offered an example that would have come out as(A) "Dogs are nice"
and on the other
(B) "For all x, if x is a dog, then it is nice." — Srap Tasmaner
What this shows is how logic can be used to clarify the somewhat ambiguous English of "Dogs are nice" by making explicit the difference between a universal and existential quantification. Of course, we could have done the same thing in English by asking "Do you mean that all dogs are nice or that some dogs are nice?".(C) There are things that are both dogs and nice
I suspect that the difference of opinion between Leontiskos and I is that he thinks of logic as an account of how we either do, or perhaps how we ought, to think. — Banno
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