Combining Texts

All the ideas for 'On Motion', 'Causality and Explanation' and 'Laudatio: Prof Ruth Barcan Marcus'

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3 ideas

4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
If a property is possible, there is something which can have it [Williamson]
     Full Idea: Barcan's axiom says if there can be something that has a certain property, then there is something that can have that property. It and its converse are not obviously correct or incorrect. They claim that it is non-contingent what individuals there are.
     From: Timothy Williamson (Laudatio: Prof Ruth Barcan Marcus [2011], p.1)
     A reaction: Williamson defends the two Barcan formulas, but the more I understand them the less plausible they sound to me.
14. Science / D. Explanation / 2. Types of Explanation / i. Explanations by mechanism
Salmon's mechanisms are processes and interactions, involving marks, or conserved quantities [Salmon, by Machamer/Darden/Craver]
     Full Idea: For Salmon mechanisms are composed of processes and interactions. The interactions are identified in terms of transmitted marks and statistical relations, or (more recently) exchanges of conserved quantities.
     From: report of Wesley Salmon (Causality and Explanation [1998], 3.1) by Machamer,P/Darden,L/Craver,C - Thinking About Mechanisms 3.1
     A reaction: They say that Salmon has too little to say about the activities that constitute a mechanism. A 'mark' doesn't sound too promising, but I quite like the exchange of conserved quantities, which gets into the guts of what is going on.
27. Natural Reality / B. Modern Physics / 1. Relativity / a. Special relativity
Motion is not absolute, but consists in relation [Leibniz]
     Full Idea: In reality motion is not something absolute, but consists in relation.
     From: Gottfried Leibniz (On Motion [1677], A6.4.1968), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 3
     A reaction: It is often thought that motion being relative was invented by Einstein, but Leibniz wholeheartedly embraced 'Galilean relativity', and refused to even consider any absolute concept of motion. Acceleration is a bit trickier than velocity.