Hi Kris,

Suppose we individuate ingredients by everything that is true about them, including their laws.  Then take an arbitrary ingredient x.  If x-particles are defined as obeying the laws in set L, it would then be true in every possible world (even worlds that don't have x-particles) that x-particles obey the laws in set L.  If so, all physical laws are the same in all logically possible worlds.  (Note: constants are laws, so they'd be included.)

What would an alternative be?  To personify a bit, the ingredients would have to "lack modal integrity".  One option would be that how they behave is controlled by whatever laws happen to be present.  On this option, physical laws would be real things that have powers over their ingredients, like gods making the sun shine.  (Or there might literally be gods that make the ingredients do what they do!)  I'd say this is pretty wild.  Another option is that it is brute in one world that, say, x-particles obey the laws in set L, but brute in a different world that x-particles obey laws of some other set L*.  My attitude is to cut out unnecessary brute facts with Ockham's razor, so I prefer the option of individuating ingredients by everything that is true about them.  This way there's no contingency about which laws are attached to which ingredients.  Rather, the appearance of contingency is due to the fact that there are possible worlds with somewhat different ingredients, but when we think of them we often fall into the trap of categorizing them under the same concepts due to their family resemblances.

But, Kris, none of this answers your question.  You want to know whether the physically possible worlds are the same as the logically possible worlds.  That depends.  Of course, all physically possible worlds are metaphysically possible, but many philosophers hold that the metaphysically possible worlds are a proper subset of the logically possible worlds.  In that case, even if the physical laws were the same in all logically possible worlds, nevertheless the physically possible worlds would be a proper subset of the logically possible worlds, not the same set.  On the other hand, if you reject the view that the metaphysically possible worlds are a proper subset of the logically possible worlds, and if you also reject contingencies between ingredients and their laws, then the physically possible worlds and the logically possible worlds are the same set.

Cheers,

James Grindeland