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Showing posts from March, 2009

Fefermans' book on Tarski available in Polish!

A Polish translation of Fefermans' Alfred Tarski: Life and Logic, translated by Joanna Golińska-Pilarek and Marian Srebrny is being published. On April 1, Warsaw University Library organizes a reception, accompanied by talks given by Jan Woleński, Mieczysław Omyła (who wrote the introduction to the Polish edition), Jan Zygmunt, Wacław Zawadowski, and THE TRANSLATORS.

If by any chance you're in Warsaw, it's in room 256 in the University Library building at Dobra 56/66 at 5 p.m. Last but not least, the posting informs, Polish doughnuts sponsored by Blikle will be served.

Pity I won't be there. :)

A contra to Putnam's 'Twin Earth'

Recall than Putnam (The Meaning of 'Meaning') argued that if a new substance is discovered with a different chemical composition but the same phenomenal qualities as certain known substance, it will not fall under the same natural kind.

His thought experiment to support this claim is this: imagine a distant planet just like ours, except the water-like substance there has different, complicated chemical composition XYZ. It looks and tastes like water etc. Imagine you travel to that planet. On Putnam's reading, even though we would initially think this is water, once we discover the difference in chemical composition, we'll reject this view and reserve the term "water" for those substances which have the structure of H2O.

Here's a historical example that these things aren't so clear-cut. For ages, the Chinese considered jade to be the most precious substance (pretty much like gold in the West). They also were very sensitive to its authenticity. Near the…

A cool lecture video online

A video from a nice session on Time Travel (Anne French, Ken Perszyn and Nick Smith) is available here. The sever hosts also Colossal Squid Lectures (they have nothing to do with time travel, afaik, it's just the title is so cool I couldn't help but mention this).

Nicholas J. J. Smith's research website links to a few fun papers about time travel as well. Among others: Why Would Time Travellers Try to Kill their Younger Selves? and Bananas Enough for Time Travel?

Norton against new logics for thought experiments

John Norton (Why Thought Experiments Do Not Transcend Empiricism) argues, among other things, that no new logical considerations are needed when we consider thought experiments in science. Here' s what he calls "evolutionary argument", in his own words (pp. 16-17 of the online version of the paper):
I think there are some reasons to believe that no new, exotic logic is called for. In outlining the general notion of logic above, I recalled the evolutionary character of the logic literature in recent times. New inferential practices create new niches and new logics evolve to fill them. Now the activity of thought experimenting in science was identified and discussed prominently a century ago by Mach (1906) and thought experiments have been used in science actively for many centuries more. So logicians and philosophers interested in science have had ample opportunity to identify any new logic that may be introduced by thought experimentation in science. So my presumption is …

A neat example of an a posteriori necessity

Recall Kripke's examples of a posteriori necessities in science were of the sort:
Gold = the element with atomic number 79
Water = the substance composed of two atoms of hydrogen and one atom of oxygen
LaPorte (Natural Kinds and Conceptual Change) provides a neat example that is more analogous to the well-known 'Hesperus=Phosphorus':
The statement 'Brontosaurus = Apatosaurus' has a history quite like that of 'Hesperus=Phosphorus'. 'Brontosaurus' was coined as a genus-term in 1874 by O.C. Marsh who thought he had discovered a new genus of dinosaur in Wyoming. As it turns out, the fossils he discovered were fossils of a dinosaur genus that he himself had already discovered and named 'Apatosaurus'. Marsh supposed that the specimen he associated with the name 'Brontosaurus' and the specimen he associated with the name 'Apatosaurus' could not be from the same genus because there was such a difference in size between the two specimens.…

Mereology and species

Laporte on species-kinds and species-individuals

I'm reading Laporte's Natural Kinds and Conceptual Change. On p. 15-16 he talks about how species don't have to be viewed as individuals, and that they can be interpreted as natural kinds. For some reason, he thinks mereology is relevant. Here is the original passage:
Suppose that the organisms of any species make up an individual, or something else that is not a kind. Call such an object a species-individual. Suppose, further, that talk about the species could satisfactorily be interpreted as talk about the species-individual. In that case, I will argue, such talk about the species could also be satisfactorily interpreted as talk about a kind. Here is why: Although the species-individual is not a kind but rather an individual, there is a property, for any such individual, of being part of that individual. For that property, just as for any other property, there is a corresponding kind, such that possession of the property is…

Ajdukiewicz and some other classics, online

If you read German, Ajdukiewicz's stuff on syntactic connectivity is available here. His paper on the notion of existence (in English) is here.

Mostowski's classification of logical systems is available here.

Tarski's paper on the notion of truth is here (in German). His "Semantic conception of truth..." in English is available here.

Reichenbach's Elements of symbolic logic are here.

Principia Mathematica can be found here.

Carnap's Empiricism, Semantics and Ontology is here, and his Meaning and Necessity is here.

Ayer's Language, Truth and Logic is here.

The Need for Abstract Entities (Church) is here.

Austin's plea for excuses is here.

Soles' paper on Russell's causal theory of meaning is located here.

Angelelli's paper on disputation in the history of logic is here.

Brian Ellis on the logic of natural kinds

I'm reading Brian Ellis' Natural Kinds and Natural Kind Reasoning (inNatural Kinds, Laws of Nature and Scientific Methodology). I'm looking especially at section 6, The Logic of Natural Kinds. There, he introduces some notation and puts forward a bunch of principles that are meant to be necessarily true about natural kinds (it's almost like reading an early piece presenting axiomatic approach to modal logic: here's the language, here's the intuitive reading, and here are the principles).

Anyway, one of the principles doesn't seem quite right, and honestly, I don't know what Ellis wanted to say there. Here's a brief description of the "logic".

Abbreviations. `
'x∈K' reads: 'x is a member of the natural kind K''PeK' reads 'P is an essential property of K''K1⊂K2' reads 'K1 is a species of K2'
'x=ey' reads: 'x is essentially the same as y''x=iy' reads: 'x and y are intrin…

Scott & Tarski consequence (basic info)

Scott consequence relations (a.k.a. multiple-conclusion consequence relations), as oppossed to Tarski consequence operations (that have single formulas as consequences) take the consequence relation to bear one set of formulas to another. What follows is a brief explanation of the relation between these two types of consequence relations.

Let A, B, C, ... stand for sentences, a, b, c, ... for finite sets of sentences, and u, v, w, ... for arbitrary sets of sentences. Relative to a language, the complement of a set u will be denoted by u'.

A Scott sequent is of the form:a⇒b
which can be read: if all sentences in a hold (=are true/are accepted/whatnot), so does at least one sentence from b [in short: asecures b]. For typographical reasons, this will also sometimes be written as "a>b".

A set of Scott sequents is a Scott consequence relation if it satisfies (for any A, a, b, c, d):
reflexivity: A⇒ AMonotonicity: If a⇒b, a⊆c, b⊆d, then c⊆d.Cut: If a⇒b, A and a,A⇒b, then a⇒b.The…