5.5542 But may we then ask such a question at all? Can we erect a symbolic form and not know whether something could correspond to it?

Does the question make sense: What must be in order that something can thereby be the case?

“Could correspond” or “can correspond” as the others have? And does that question make sense? It seems to. My child must be so that I can be a parent. If existence is not a predicate, can predicates depend in any way on existence? Mustn’t possibilities of being this way or that be independent of what happens to exist or not? These possibilities of being, after all, are very close to Tractarian objects, and they are logical, not metaphysical/ontological. Wittgenstein says, Letters to Ogden pp. 33-34, that the correct answer to the initial question “would be, that we may NOT!”

Black (p. 304): “The answers to all three questions are clearly intended to be in the negative. But it is ironical to notice that the third question expresses one of the main preoccupations of the Tractatus.”