From Propositions 6.4-6.54, the Tractatus shifts its focus from primarily logical considerations to what may be considered more traditionally philosophical foci (God, ethics, meta-ethics, death, the will) and, less traditionally along with these, the mystical. The philosophy of language presented in the Tractatus attempts to demonstrate just what the limits of language are- to delineate precisely what can and cannot be sensically said. Among the sensibly sayable for Wittgenstein are the propositions of natural science, and to the nonsensical, or unsayable, those subjects associated with philosophy traditionally- ethics and metaphysics, for instance. Curiously, on this score, the penultimate proposition of the Tractatus, proposition 6.54, states that once one understands the propositions of the Tractatus, he will recognize that they are senseless, and that they must be thrown away. Proposition 6.54, then, presents a difficult interpretative problem. If the so-called ‘picture theory’ of meaning is correct, and it is impossible to represent logical form, then the theory, by trying to say something about how language and the world must be for there to be meaning, is self-undermining. This is to say that the ‘picture theory’ of meaning itself requires that something be said about the logical form sentences must share with reality for meaning to be possible. This requires doing precisely what the ‘picture theory’ of meaning precludes. It would appear, then, that the metaphysics and the philosophy of language endorsed by the Tractatus give rise to a paradox: for the Tractatus to be true, it will necessarily have to be nonsense by self-application; but for this self-application to render the propositions of the Tractatus nonsense (in the Tractarian sense), then the Tractatus must be true.