 In fact, Whitehead and Russell make the claim: “that what we call a ‘proposition’ (in the sense in which this is distinguished from the phrase expressing it) is not a single entity at all. That is to say, the phrase which expresses a proposition is what we call an ‘incomplete symbol’ …” They seem to be aware that this fragmenting of propositions requires a similar fragmenting of propositional functions. But the contextual definition or definitions that are implicitly promised by the “incomplete symbol” characterization are never fully supplied, and it is in particular how they would explain away the use of bound propositional and functional variables. If some things that are said by Russell in IV and V of his Introduction to the second edition may be taken as an indication of what is intended, it is probable that the contextual definitions would not stand scrutiny.