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All the ideas for 'Katzav on limitations of dispositions', 'works' and 'A Completeness Theorem in Modal Logic'

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10 ideas

4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
Propositional modal logic has been proved to be complete [Kripke, by Feferman/Feferman]
     Full Idea: At the age of 19 Saul Kripke published a completeness proof of propositional modal logic.
     From: report of Saul A. Kripke (A Completeness Theorem in Modal Logic [1959]) by Feferman / Feferman - Alfred Tarski: life and logic Int V
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / a. Systems of modal logic
With possible worlds, S4 and S5 are sound and complete, but S1-S3 are not even sound [Kripke, by Rossberg]
     Full Idea: Kripke gave a possible worlds semantics to a whole range of modal logics, and S4 and S5 turned out to be both sound and complete with this semantics. Hence more systems could be designed. S1-S3 failed in soundness, leading to 'impossible worlds'.
     From: report of Saul A. Kripke (A Completeness Theorem in Modal Logic [1959]) by Marcus Rossberg - First-order Logic, 2nd-order, Completeness §4
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
The variable domain approach to quantified modal logic invalidates the Barcan Formula [Kripke, by Simchen]
     Full Idea: Kripke's variable domain approach to quantified modal logic famously invalidates the Barcan Formula.
     From: report of Saul A. Kripke (A Completeness Theorem in Modal Logic [1959]) by Ori Simchen - The Barcan Formula and Metaphysics §3
     A reaction: [p.9 and p.16] In a single combined domain all the possibilia must be present, but with variable domains objects in remote domains may not exist in your local domain. BF is committed to those possible objects.
The Barcan formulas fail in models with varying domains [Kripke, by Williamson]
     Full Idea: Kripke showed that the Barcan formula ∀x□A⊃□∀xA and its converse fail in models which require varying domains.
     From: report of Saul A. Kripke (A Completeness Theorem in Modal Logic [1959]) by Timothy Williamson - Truthmakers and Converse Barcan Formula §1
     A reaction: I think this is why I reject the Barcan formulas for metaphysics - because the domain of metaphysics should be seen as varying, since some objects are possible in some contexts and not in others. Hmm…
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
There are two sides to men - the pleasantly social, and the violent and creative [Diderot, by Berlin]
     Full Idea: Diderot is among the first to preach that there are two men: the artificial man, who belongs in society and seeks to please, and the violent, bold, criminal instinct of a man who wishes to break out (and, if controlled, is responsible for works of genius.
     From: report of Denis Diderot (works [1769], Ch.3) by Isaiah Berlin - The Roots of Romanticism
     A reaction: This has an obvious ancestor in Plato's picture (esp. in 'Phaedrus') of the two conflicting sides to the psuché, which seem to be reason and emotion. In Diderot, though, the suppressed man has virtues, which Plato would deny.
26. Natural Theory / B. Natural Kinds / 1. Natural Kinds
The natural kinds are objects, processes and properties/relations [Ellis]
     Full Idea: There are three hierarchies of natural kinds: objects or substances (substantive universals), events or processes (dynamic universals), and properties or relations (tropic universals).
     From: Brian Ellis (Katzav on limitations of dispositions [2005], 91)
     A reaction: Most interesting here is the identifying of natural kinds with universals, making universals into the families of nature. Universals are high-level sets of natural kinds. To grasp universals you must see patterns, and infer the underlying order.
26. Natural Theory / D. Laws of Nature / 2. Types of Laws
Least action is not a causal law, but a 'global law', describing a global essence [Ellis]
     Full Idea: The principle of least action is not a causal law, but is what I call a 'global law', which describes the essence of the global kind, which every object in the universe necessarily instantiates.
     From: Brian Ellis (Katzav on limitations of dispositions [2005])
     A reaction: As a fan of essentialism I find this persuasive. If I inherit part of my essence from being a mammal, I inherit other parts of my essence from being an object, and all objects would share that essence, so it would look like a 'law' for all objects.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / a. Scientific essentialism
A species requires a genus, and its essence includes the essence of the genus [Ellis]
     Full Idea: A specific universal can exist only if the generic universal of which it is a species exists, but generic universals don't depend on species; …the essence of any genus is included in its species, but not conversely.
     From: Brian Ellis (Katzav on limitations of dispositions [2005], 91)
     A reaction: Thus the species 'electron' would be part of the genus 'lepton', or 'human' part of 'mammal'. The point of all this is to show how individual items connect up with the rest of the universe, giving rise to universal laws, such as Least Action.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / c. Essence and laws
A hierarchy of natural kinds is elaborate ontology, but needed to explain natural laws [Ellis]
     Full Idea: The hierarchy of natural kinds proposed by essentialism may be more elaborate than is strictly required for purposes of ontology, but it is necessary to explain the necessity of the laws of nature, and the universal applicability of global principles.
     From: Brian Ellis (Katzav on limitations of dispositions [2005], 91)
     A reaction: I am all in favour of elaborating ontology in the name of best explanation. There seem, though, to be some remaining ontological questions at the point where the explanations of essentialism run out.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / d. Knowing essences
Without general principles, we couldn't predict the behaviour of dispositional properties [Ellis]
     Full Idea: It is objected to dispositionalism that without the principle of least action, or some general principle of equal power, the specific dispositional properties of things could tell us very little about how these things would be disposed to behave.
     From: Brian Ellis (Katzav on limitations of dispositions [2005], 90)
     A reaction: Ellis attempts to meet this criticism, by placing dispositional properties within a hierarchy of broader properties. There remains a nagging doubt about how essentialism can account for space, time, order, and the existence of essences.