He prefaces his book with that exact kind of argumentation. It bothers me a bit because he is so on point with many other things.

Regarding "preferrable," Molyneaux's idea is demonstrated in the example he gives about two men locked in a room. If they both have an ipod, would it be most universally prefferable (he distinguishes between prefferable and preferred) that they each refrain from stealing the others Ipod. It cannot be a universal rule that one steal from the other, since one would be without and the other would have ill-gotten gains. It cannot be universally preferable that they both steal from one another, since no one will have gained and both would have lost. Thus is can only be universally preferred that they each retain what is theirs, and only get when it is agreed to exchange between the two of them.