   Russell held that they are nevertheless distinct propositions (POM,  74). This was perhaps in part due to the difference in grammatical structure, and perhaps also because the former appears only to be about numbers, whereas the latter is about all things, whether numbers or not. Instead, Russell thought that the proposition corresponding to (1) contains as a constituent the denoting concept all numbers. As Russell explained them, when denoting concepts  occur in a proposition, the proposition is not about them but about  other entities to which the denoting concepts bear a special relation. So when the denoting concept all numbers occurs in a proposition, the proposition is not about the denoting concept, but instead about 1 and 2 and 3, etc.