 Bush changes his position, sitting at t and standing at t'. Then (10) is true at t and false at t'. (Not all would agree that the proposition, as opposed to tensed sentence, varies its truth value across time. We discuss this below.) Suppose that (10) is a singular proposition with Bush as a constituent. What is that constituent like? No answer seems to satisfy. By the law of excluded middle, either it satisfies the condition ‘x is sitting’ or it doesn't. If it does, then why is (10) false, as it is at t'; if it doesn't, then it why is (10) true, as it is at t? It also seems strange to think of that (10) itself as changing in its constituents across time, as one and the same proposition is being evaluated at the different times.