Ludwig Wittgenstein:

“Thought must be something unique.” When we say, and mean, that such-and-such is the case, we — and our meaning — do not stop anywhere short of the fact; but we mean: this — is — so. But this paradox (which has the form of a truism) can also be expressed in this way: Thought can be of what is not the case.

Other illusions come from various quarters to attach themselves to the special one spoken of here. Thought, language, now appear to us as the unique correlate, picture, of the world. These concepts: proposition, language, thought, world, stand in line one behind the other, each equivalent to each. (But what are these words to be used for now? The language-game in which they are to be applied is missing.)

Thought is surrounded by a halo. — Its essence, logic, presents an order, in fact the a priori order of the world: that is, the order of possibilities, which must be common to both world and thought. But this order, it seems, must be utterly simple. It is prior to all experience, must run through all experience; no empirical cloudiness or uncertainty can be allowed to affect it. — It must rather be of the purest crystal. But this crystal does not appear as an abstraction; but as something concrete, indeed, as the most concrete — as it were the hardest thing there is

Here it is difficult as it were to keep our heads up, — to see that we must stick to the subjects of our everyday thinking, and not go astray and imagine that we have to describe extreme subtleties, which in turn we are after all quite unable to describe with the means at our disposal. We feel as if we had to repair a torn spider’s web with our fingers.

Language (or thought?) is something unique” — this proves to be a superstition (not a mistake!), itself produced by grammatical illusions. And now the impressiveness retreats to these illusions, to the problems.

“But you will surely admit that there is a difference between pain — behavior accompanied by pain and pain — behavior without any pain?” — Admit it? What greater difference could there be? — “And yet you again and again reach the conclusion that the sensation itself is a nothing.” — Not at all. It is not a something, but not a nothing either! The conclusion was only that a nothing would serve just as well as a something about which nothing could be said. We have only rejected the grammar which tries to force itself on us here.
… The paradox disappears only if we make a radical break with the idea that language always functions in one way, always serves the same purpose: to convey thoughts — which may be about houses, pains, and evil, or anything else you please.