ABSTRACT
A fragile vase is struck with only a moderate amount of force and breaks. It may be possible to describe its breaking in terms of some micro-structural property of the vase, B. Thus the breaking of the glass is caused by the combination of its being B and its being struck. In explaining the breaking we have not yet mentioned the vase’s fragility. It possesses the fragility in virtue of its possessing B. Its fragility supervenes, relative to the laws of nature, on its being B, which is to say that in all possible worlds that share the laws of the actual world, objects with B are fragile. May we also explain the vase’s breaking by reference to the combination of its being fragile and its being struck?
