Just a quick reminder to metaphysicians in the Leeds area: the CMM seminar today is going to be on Hawthorne's paper "Lewis on Quantity" from his Metaphysical Essays.
A quick puzzle I'm having over Lewis-interpretation. Suppose that in the actual world, a fundamental property P is instantiated by pointy things. Can that very same fundamental property be instantiated in another world by non-pointy things?
The point is that in characterizing Humean supervenience, Lewis mentions ways it might fail e.g. there being "emergent natural properties of more-than-point sized things". He insists that, though such properties are possible, they would have to occur in worlds featuring properties "altogether alien to this world". But that wouldn't be the case if it were a contingent feature of the properties we found lying around this world, that they hold of pointy things rather than more-than-point-sized things.
Maybe the moral is that the mereological structure of the instantiators of a property is *not* a matter that can vary from world to world, for Lewis. If so, it seems a pretty strange claimed of necessity.