   The theory of “On Denoting” did away with Russell’s temptation to regard grammar as a very reliable guide towards understanding the structure or make-up of a proposition. Especially important in this regard is the notion of an “incomplete symbol”, by which Russell understood an expression that can be meaningful in the context of its use within a sentence, but does not by itself correspond to a constituent or unified part of the corresponding proposition. According to the theory of “On Denoting”, phrases such as “the King of France”, or “the author of Waverly” were to be understood as “incomplete symbols” in this sense. The general notion of an “incomplete symbol” was applied by Russell in ways beyond the theory of descriptions, and perhaps most importantly, to his understanding of classes.