Re: [PEIRCE-L] Problems in mixing quantifiers with modal logic (was Delta Existential Graphs

2024-03-08 Thread Jeffrey Brian Downard
Hello John, Jon, List, Peirce examines both first and second intentional logics. The distinction appears to be similar, in some respects, to the contemporary distinction between first and second order logics. Here, for instance, is an SEP entry on higher order logics:

Re: [PEIRCE-L] Problems in mixing quantifiers with modal logic (was Delta Existential Graphs

2024-03-07 Thread Jon Alan Schmidt
John, List: It looks like you sent the message quoted below only to me, but I assume that you intended it for the entire List, so I am replying accordingly. JFS: In the copy of your note, included below, please note that the five EGs are *BETA *graphs. The lines of identity refer to things that

Re: [PEIRCE-L] Problems in mixing quantifiers with modal logic (was Delta Existential Graphs

2024-03-07 Thread Jon Alan Schmidt
John, List: JFS: In his letter on Delta graphs, Peirce was breaking new ground. He was proposing a totally new foundation for modal logic, based on metalanguage. There is no "letter on Delta graphs." Peirce wrote only *one sentence* that mentions them in a letter to Risteen (R L376, 1909 Dec

Re: [PEIRCE-L] Problems in mixing quantifiers with modal logic (was Delta Existential Graphs

2024-03-06 Thread John F Sowa
Gary, In his letter on Delta graphs, Peirce was breaking new ground. He was proposing a totally new foundation for modal logic, based on metalanguage. The important references are in the future, not the past. For Peirce's past, the most relevant references were cited and discussed many

Re: [PEIRCE-L] Problems in mixing quantifiers with modal logic (was Delta Existential Graphs

2024-03-05 Thread Gary Richmond
John, I have been following this exchange between you and Jon Alan with considerable interest. Thank you both for discussing these most interesting -- and I think, important matters relating to modals, Delta graphs, etc. -- in the generally collegial manner in which you have been proceeding. You

Re: [PEIRCE-L] Problems in mixing quantifiers with modal logic (was Delta Existential Graphs

2024-03-05 Thread John F Sowa
Jon, The first point to emphasize is that Peirce's primary goal in the last decade of his life was to provide a proof of pragmatism. That would require a system of logic that could express and analyze rather sophisticated texts about science. The metalanguage of the IKL logic in 2006 is very

Re: [PEIRCE-L] Problems in mixing quantifiers with modal logic (was Delta Existential Graphs

2024-03-04 Thread Jon Alan Schmidt
John, List: JFS: One reason why I did not respond in detail to your previous note (copied below) is that your citations to the writings by Dunn and Goble only apply to PROPOSITIONAL modal logic (no quantifiers). I have acknowledged this all along--my candidate for Delta EGs is an extension of

[PEIRCE-L] Problems in mixing quantifiers with modal logic (was Delta Existential Graphs

2024-03-04 Thread John F Sowa
Jon, One reason why I did not respond in detail to your previous note (copied below) is that your citations to the writings by Dunn and Goble only apply to PROPOSITIONAL modal logic (no quantifiers). Every version of modal logic that Peirce developed included existential graphs as the base