 One possible realist response is that the concept of truth is actually very simple, and it is spurious to demand that one always be able to determine whether a concept applies. As to the first part, it is often argued that all there is to the notion of truth is what is given by the formula “‘\(p\)’ is true if and only if \(p\)”. The function of the truth-predicate is to disquote sentences in the sense of undoing the effects of quotation—thus all that one is saying in calling the sentence “Yeti are vicious” true is that Yeti are vicious.