INDEPENDENTLY MOTIVATING THE KOCHEN-DIEKS MODAL INTERPRETATION OF QUANTUM-MECHANICS

The distinguishing feature of 'modal' interpretations of quantum mecha nics is their abandonment of the orthodox eigenstate-eigenvalue rule, which says that an observable possesses a definite value if and only i f the system is in an eigenstate of that observable. Kochen's and Diek s' new biorthogonal decomposition rule for picking out which observabl es have definite values is designed specifically to overcome the chief problem generated by orthodoxy's rule, the measurement problem, while avoiding the no-hidden-variable theorems. Otherwise, their new rule s eems completely ad hoc. The ad hoc charge can only be laid to rest if there is some way to give Kochen's and Dieks' rule for picking out whi ch observables have definite values some independent motivation. And t here is, or so I will argue here. Specifically, I shall show that thei rs is the only rule able to save Schrodinger's cat from a fate worse t han death, and sidestep the Bell-Kochen-Specker no-hidden-variables th eorem, once we impose four independently natural conditions on such ru les.