 An important related criticism, not acknowledged by Russell in subsequent writings (it appeared after his response to Jones in “Knowledge by Acquaintance and Knowledge by Description”) is a critique of a famous passage in Principia Mathematica. In arguing that descriptions are incomplete symbols and have no meaning in isolation, Russell claims that although ‘Scott is the author of Waverley’ expresses an identity, ‘the author of Waverley’ cannot be a name. If it were, then it would be a value of c in the propositional function ‘Scott is c’. But this would mean that ‘Scott is the author of Waverley’ expresses what ‘Scott is Scott’ expresses, which is absurd: