  Now, it was said above that Leibniz excludes purely extrinsic denominations (or relational properties) from the kinds of properties that are constitutive of an individual. To allow purely extrinsic denominations would be to accept the possibility that that two things could be discernible in terms of their relational properties while being identical in terms of their intrinsic properties, for their relational properties would not follow from their intrinsic properties. (Again, if relational properties were allowed to factor into the nature of an individual, then PII would be relatively weak. Of course two things that exist in different spatio-temporal locations are distinct, and that is what Leibniz admits in the passage from the New Essays above.) But if we follow Leibniz in excluding such relational properties as difference-making properties and reflect on the above argument, then we see that worlds are distinguished in terms of intrinsic properties of individuals and that this difference has a bearing on the relative greatness or perfection of a world. Again, let a and b be indiscernible but occupying mirror positions in W and W*. How could we ever say that W was more worthy of God's choice than W*? We could not. There must be a reason why a is here and b is there, and this reason has to do with the intrinsic properties of a and b. In other words, even the relational properties must be somehow derivative of the intrinsic properties of substances.