We cannot say what we cannot think. The subject as limit of the world is not in the world. The nature of the world remains independent of my intentions. Things that cannot be put into words cannot be shown.
Every proposition results from successive applications of joint denial to elementary propositions.
Proofs in logic are necessary for the display of logical truths. The law of induction is a law of logic. Describing the world by Newtonian mechanics tells us nothing about the world. To say that an object is both red and green at the same time is to utter a contingency. Philosophy should be relegated to the study of metaphysics.