  But as Williamson (1994, 187–198) argues, these principles are inconsistent with the claim that there is a truth-valueless proposition: For suppose that the proposition that \(p\) is neither true nor false. From (T), since it is not true that \(p\), then not \(p\). From (F), since it is not false that \(p\), then not not \(p\). We have now arrived at a direct contradiction: not-\(p\) and not-not-\(p\).