The limits of my language means the limits of my world. - Ludwig Wittgenstein

The sense of the world must lie outside the world. In the world everything is as it is, and everything happens as it does happen: in it no value exists — and if it did exist, it would have no value. If there is any value that does have value, it must lie outside the whole sphere of what happens and is the case. For all that happens and is the case is accidental. What makes it non-accidental cannot lie within the world, since if it did it would itself be accidental. It must lie outside the world.

Nothing in the visual field allows you to infer that it is seen by an eye.

— 'A thing is identical with itself.' — There is no finer example of a useless proposition [...]. It is as if in imagination we put a thing into its own shape and saw that it fitted.