“On Whether Some Laws are Necessary” Analysis 62, 257-270 (2002)


In “Necessarily, Salt Dissolves in Water” (Analysis 61 (2001)) I argued that because the laws required for the existence of salt entail the laws that ensure dissolving in water, there is no possible world in which salt exists but fails to dissolve in water. In this paper I respond to criticisms from Helen Beebee and Stathis Psillos (Analysis 62 (2002)). I also introduce the ‘down-and-up’ structure, generalising the case. Whether or not this structure is instantiated is a matter for a posteriori discovery. Hence not only are some laws necessary (but known a posteriori), but furthermore whether a given law is necessary or contingent will also be a matter of a posteriori discovery.