  On this view, individual objects of a particular kind are qualitatively identical. They are not individuated by an haecceity or primitive thisness. Classical particles can be and often are so regarded. Classical particles could be so regarded because if a principle of impenetrability is adhered to, no two such particles ever have all the same spatio-temporal properties. The bundle theory of individuation was developed by empiricists to account for the individuation of physical objects while only quantifying over properties that are within the reach of natural science. This is a standard metaphysical position that implies nothing so radical as any version of OSR. Its interest lies in the fact that on this view it would seem that the Principle of the Identity of Indiscernibles (PII), restricted so that identity involving properties are not in its scope, must be true. If so there are some properties (perhaps including spatio-temporal properties) that distinguish each thing from every other thing, and the identity and individuality of physical objects can be reduced to other facts about them.