A DICTUM fundamental in the Quinian theory of singular terms is the following: 1 (1) No singular term which permits a true statement including it to be turned into a falsehood (via existential generalization with respect to that term) can be a substituend of a variable. Following (1), for example, "Pegasus" cannot be taken as a substituend of the variable "x" because the inference (2) There is no such thing as Pegasus, Therefore, (Ox) (there is no such thing as x), is invalid. Hence, no statement in which "Pegasus" occurs can be a premise in a valid inference where a premise is (a) an instance of a logical formula or is (b) an instance of a sentential part of a logical formula.2 For example, (3) Pegasus is a horse, which, after Quine, is false because it applies a simple predicate to 1