 The inability of the Kripkean language to express its own undefined predicate also means that we cannot in the Kripkean object-language express a statement such as: “The liar sentence is undefined”. In fact in Kripke’s language \(L_{\gamma}\), the liar sentence \(is\) undefined, so the previous sentence expresses a truth about \(L_{\gamma}\) that cannot be expressed within \(L_{\gamma}\) itself (hence the language is expressively incomplete). To express the true statement “The liar sentence is undefined”, we are forced to ascend into a meta-language of \(L_{\gamma}\). As Kripke (1975) himself puts it: “The ghost of the Tarski hierarchy is still with us.” 