Combining Texts

All the ideas for 'fragments/reports', 'Barcan Formulae' and 'Merely Possible Propositions'

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5 ideas

4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
Barcan:nothing comes into existence; Converse:nothing goes out; Both:domain is unchanging [Vervloesem]
     Full Idea: Intuitively, the Barcan formula says that nothing comes into existence when moving from a possible world to an alternative world. The converse says that nothing goes out of existence. Together they say the domain of quantification is fixed for all worlds.
     From: Koen Vervloesem (Barcan Formulae [2010])
     A reaction: Stated so clearly, they sound absurd. The sensible idea, I suppose, is that you can refer to all the things from any world, but that doesn't mean they are possible. Shades of Meinong. 'Square circles' are not possible.
9. Objects / A. Existence of Objects / 4. Impossible objects
Predicates can't apply to what doesn't exist [Stalnaker]
     Full Idea: Nothing can be predicated of something which does not exist.
     From: Robert C. Stalnaker (Merely Possible Propositions [2010], p.28)
     A reaction: [He says he is 'agreeing with Plantinga' on this] This seems very puzzling, as you can obviously say that dragons do not exist, but they breathe fire. Why can't you attach predicates to hypothetical objects?
19. Language / D. Propositions / 3. Concrete Propositions
A 'Russellian proposition' is an ordered sequence of individual, properties and relations [Stalnaker]
     Full Idea: A 'Russellian proposition' is an ordered sequence containing the individual, along with properties and relations.
     From: Robert C. Stalnaker (Merely Possible Propositions [2010], p.22)
     A reaction: Since Russell took properties and relations to be features of reality, this made the whole proposition a feature of reality. This is utterly different from what I understand by the word 'proposition', which is a feature of thought, not of the world.
26. Natural Theory / A. Speculations on Nature / 5. Infinite in Nature
Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius]
     Full Idea: Archelaus was the first person to say that the universe is boundless.
     From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3
27. Natural Reality / G. Biology / 3. Evolution
Archelaus said life began in a primeval slime [Archelaus, by Schofield]
     Full Idea: Archelaus wrote that life on Earth began in a primeval slime.
     From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus
     A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea.