 Thus we already see that Russell differs from Frege on what kinds of things can be constituents of propositions. For Frege, all constituents of propositions are senses. For Russell, a man or a mountain can be a constituent of a proposition. In a now famous correspondence with Frege, Russell replied to Frege’s assertion that the sense of the name ‘Mont Blanc’, and not Mont Blanc itself “with all its snowfields”, occurs in the proposition/thought that Mont Blanc is 4,000 meters high, by saying: 