> On 8 Jul 2019, at 12:42, Philip Thrift <[email protected]> wrote: > > > > On Monday, July 8, 2019 at 4:58:32 AM UTC-5, Bruno Marchal wrote: > >> On 6 Jul 2019, at 13:32, Philip Thrift <[email protected] <javascript:>> >> wrote: >> >> >> >> On Saturday, July 6, 2019 at 1:42:20 AM UTC-5, Bruno Marchal wrote: >> >>> On 6 Jul 2019, at 05:57, Philip Thrift <[email protected] <>> wrote: >> >> >> Whatever logic it is, its semantics (of a theory in that logic) is the >> elephant in the room. >> >> - https://en.wikipedia.org/wiki/Semantics_of_logic >> <https://en.wikipedia.org/wiki/Semantics_of_logic> >> - https://en.wikipedia.org/wiki/Model_theory >> <https://en.wikipedia.org/wiki/Model_theory> >> e.g. Whereas universal algebra provides the semantics for a signature, logic >> provides the syntax. >> - https://plato.stanford.edu/entries/model-theory/ >> <https://plato.stanford.edu/entries/model-theory/> >> >> Semantics is the wild, wild west of logic. > > > You might try to make a point, perhaps. Semantic is obviously very important. > > Logic can be divided in three chapters: > > - theory of theories and proofs (cf Gödel) > > - semantics (Model theory) (cf Lowenheim, Skolem and Tarski, Mostowski, …) > > - the relation between, theories and models, that is the study of (all) > theories and all their semantics, usually through completeness and > incompleteness theorems. > > Semantic is the heart of “modern logic”. I do avoid using it here to much, > because it is quickly rather technical. I hope people have some idea that the > structure (N, 0, +, *) (which is the set N with the usual standard > interpretation of + and *) is a model of both RA and PA. I might say a bit > more in the glossary I am preparing. All “rich” theories have infinitely many > non isomorphic models, and by incompleteness no theories at all can study its > own semantics, but some theories can still say a lot about it, like its own > incompleteness. > > Bruno > > > > Semantics is real thing, so to speak, to me. > > There are two types of semantics: > > Fictional - regarding all the mathematical structures of standard model > theory you refer to above (Hartry Field)
The non standard model would be less fictional? The word “fiction” can be misleading. I prefer to use “immaterial”, or “spiritual”, or “mental”, perhaps. > Material - things/entities in the material world Those are important, but if we assume mechanism, I don’t think we can assume matter, but we can explain its appearances from the machine’s consciousness theory (theology) and test it empirically. Up to now, the evidences favours mechanism. > > > Semantics and substrates are connected, it not identical. That's my blog. I can’t really make sense of this. > > Also > > There is in my opinion no important theoretical difference between natural > languages and the artificial languages of logicians. (Richard Montague) For a monist, the difference between natural and artificial is artificial, and indeed natural for those entities which develop a big ego and feel different. Of course there is a difference between the formal languages and the “natural” languages, and Richard Montague attempt to develop a sort of polymodal rich lambda calculus for the treatment of natural language is very interesting. So I appreciate your opinion that there is no fundamental difference between those type of languages. When I was younger I have made a universal programming language (ANIMA° which was also a subset of natural language (English). You could ask the computer things like, “could you please find a file with some document on number in my computer, and if not, on the net?”. But it was very slow, and people prefer shortcuts … Bruno > > @philipthrift > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/4c4884c5-a658-4112-9602-dc8decf3f5aa%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/4c4884c5-a658-4112-9602-dc8decf3f5aa%40googlegroups.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/A32397A8-28FC-48C9-9275-E452AEDEC370%40ulb.ac.be.
