In a recent post in his blog, Woit comments on a philosophy of science article by a philosopher who claims that the dualities in string theory imply the "dissolution of the ontological object". His claim is that because the dualities in string theory can describe two different sorts of behaviours of strings in spacetime which are indistinguishable from each other empirically, there is no more basis for a traditional ontological object. However, he keeps on referring to the "string", isn't the string itself a fundamental entity and the traditional ontological object. Also, could anybody provide any insight in the light of the string landscape, where the extremely large number of separate vacua can be interrelated by dualities? Also, what is the "ontological object" in loop quantum gravity? Any comments or insights would be appreciated!