 adding that “[t]he concept of number is… the general form of a number” (6.022). As Frascolla (and Marion after him) have pointed out, “the general form of a proposition is a particular case of the general form of an ‘operation’” (Marion 1998: 21), and all three general forms (i.e., of operation, proposition, and natural number) are modeled on the variable presented at (5.2522) (Marion 1998: 22). Defining “[a]n operation [as] the expression of a relation between the structures of its result and of its bases” (5.22), Wittgenstein states that whereas “[a] function cannot be its own argument,… an operation can take one of its own results as its base” (5.251).